Researcher Database

Kohsuke Kudo
Faculty of Medicine Internal Medicine Department of Radiology
Professor

Researcher Profile and Settings

Affiliation

  • Faculty of Medicine Internal Medicine Department of Radiology

Job Title

  • Professor

Degree

  • PhD(2003/03 Hokkaido University)

J-Global ID

Research Interests

  • 神経放射線診断 CT MRI   Neuroradiology CT Perfusion MR Perfusion   

Research Areas

  • Life sciences / Radiology

Academic & Professional Experience

  • 2019/08 - Today Hokkaido University Graduate School of Medicine Department of Diagnostic Imaging Professor
  • 2013/04 - 2019/07 Hokkaido University Hospital Department of Diagnostic and Interventional Radiology Associate Professor
  • 2011/04 - 2013/03 Iwate Medical University Assistant Professor
  • 2008/04 - 2011/03 Iwate Medical University Advanced Medical Science Research Center Lecturer
  • 2007/04 - 2008/03 Hokkaido University Hospital Department of Radiology Assistant Professor
  • 2006/05 - 2007/03 Wayne State University Visiting Assistant Professor
  • 2004/04 - 2006/04 Hokkaido Univeristy Graduate School of Medicine Department of Radiology Assistant Professor

Education

  • 1999/04 - 2003/03  Hokkaido University  Graduate School of Medicine  Department of Radiology
  • 1989/04 - 1995/03  Hokkaido University  School of Medicine

Association Memberships

  • Japan Society for CNS Computed Imaging   Japanese Society of Cerebral Blood Flow and Metabolism   International Society for Magnetic Resonance in Medicine   Japanese Society for Magnetic Resonance in Medicine   The Japanese Society of Neuroradiology   Radiological Society of North America   Japan Radiological Society   

Research Activities

Published Papers

  • Noriyuki Fujima, Hiroyuki Kameda, Yukie Shimizu, Taisuke Harada, Khin Khin Tha, Masami Yoneyama, Kohsuke Kudo
    Magnetic resonance imaging 69 81 - 87 2020/06 [Refereed][Not invited]
     
    PURPOSE: To investigate the utility of diffusion-weighted arterial spin labeling (DW-ASL) for detecting the progression of brain white matter lesions. MATERIALS AND METHODS: A total of 492 regions of interest (ROIs) in 41 patients were prospectively analyzed. DW-ASL was performed using the diffusion gradient prepulse of five b-values (0, 25, 60, 102, and 189) before the ASL readout. We calculated the water exchange rate (Kw) with post-processing using the ASL signal information for each b-value. The cerebral blood flow (CBF) was also calculated using b0 images. Using the signal information in FLAIR (fluid-attenuated inversion recovery) images, we classified the severity of white matter lesions into three grades: non-lesion, moderate, and severe. In addition, the normal Kw level was measured from DW-ASL data of 60 ROIs in five control subjects. The degree of variance of the Kw values (Kw-var) was calculated by squaring the value of the difference between each Kw value and the normal Kw level. All patient's ROIs were divided into non-progressive and progressive white matter lesions by comparing the present FLAIR images with those obtained 2 years before this acquisition. RESULTS: Compared to the non-progressive group, the progressive group had significantly lower CBF, significantly higher severity grades in FLAIR, and significantly greater Kw-var values. In a receiver operator characteristic curve analysis, a high area under the curve (AUC) of 0.89 was obtained with the use of Kw-var. In contrast, the AUCs of 0.59 for CBF and 0.72 for severity grades in FLAIR were obtained. CONCLUSIONS: The DW-ASL technique can be useful to detect the progression of brain white matter lesions. This technique will become a clinical tool for patients with various degrees of white matter lesions.
  • T Shima, N Fujima, S Yamano, K Kudo, K Hirata, K Minowa
    Clinical radiology 75 (5) 397.e15-397.e21  2020/05 [Refereed][Not invited]
     
    AIM: To evaluate and compare diffusion-weighted imaging (DWI) parameters derived from a non-Gaussian fitting model and positron-emission tomography (PET) parameters derived from 18F-fluoromisonidazole-PET (FMISO-PET) in patients with oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Primary sites were evaluated prospectively in 18 patients. DWI was performed using six b-values (0-2,500). Diffusion-related parameters of kurtosis value (K), the kurtosis-corrected diffusion coefficient (DK), diffusion heterogeneity (α), distributed diffusion coefficient (DDC), the slow diffusion coefficient (Dslow), and the apparent diffusion coefficient (ADC) were calculated from four diffusion-fitting models. Maximal standardised uptake values (SUVmax), mean standardised uptake values (SUVmean), and the tumour-to-muscle ration (TMR) of the SUV value were calculated for FMISO-PET. Spearman's correlation coefficient was used to evaluate the correlation between each non-Gaussian diffusion model parameters and PET parameter. RESULTS: There was moderate correlation between FMISO-PET SUVmax and Dslow (ρ=-0.45, p=0.06). In addition, there was good correlation between TMRmax and five non-Gaussian diffusion model parameters (K: ρ=0.65, p=0.004, DK: ρ=-0.72, p=0.0008, DDC: ρ=-0.75, p=0.0003, ADC: ρ=-0.74, p=0.0005, and Dslow: ρ= -0.65, p=0.003), and between TMRmean and five non-Gaussian model parameters (K: ρ=0.64, p=0.005, DK: ρ=-0.61, p=0.007, DDC: ρ=-0.63, p=0.005, ADC: ρ=-0.61, p=0.007, and Dslow: ρ=-0.56, p=0.015). CONCLUSION: Non-Gaussian diffusion model parameters can be related to tumour hypoxia.
  • Daisuke Sawamura, Hisashi Narita, Naoki Hashimoto, Shin Nakagawa, Hiroyuki Hamaguchi, Noriyuki Fujima, Kohsuke Kudo, Hiroki Shirato, Khin K Tha
    Journal of magnetic resonance imaging : JMRI 2020/04/23 [Refereed][Not invited]
     
    BACKGROUND: Identifying structural and functional abnormalities in bipolar (BD) and major depressive disorders (MDD) is important for understanding biological processes. HYPOTHESIS: Diffusion kurtosis imaging (DKI) may be able to detect the brain's microstructural alterations in BD and MDD and any differences between the two. STUDY TYPE: Prospective. SUBJECTS: In all, 16 BD patients, 19 MDD patients, and 20 age- and gender-matched healthy volunteers. FIELD STRENGTH/SEQUENCE: DKI at 3.0T. ASSESSMENT: The major DKI indices of the brain were compared voxel-by-voxel among the three groups. Significantly different voxels were tested for correlation with clinical variables (ie, Young Mania Rating Scale [YMRS], 17-item Hamilton Depression Rating Scale [17-HDRS], Montgomery-Åsberg Depression Rating Scale, total disease duration, duration of current episode, and the number of past manic/depressive episodes). The performance of the DKI indices in identifying microstructural alterations was estimated. STATISTICAL TESTS: One-way analysis of variance (ANOVA) was used for group comparison of DKI indices. The performance of these indices in detecting microstructural alterations was determined by receiver operating characteristic (ROC) analysis. Pearson's product-moment correlation analyses were used to test the correlations of these indices with clinical variables. RESULTS: DKI revealed widespread microstructural alterations across the brain in each disorder (P < 0.05). Some were significantly different between the two disorders. Mean kurtosis (MK) in the gray matter of the right inferior parietal lobe was able to distinguish BD and MDD with an accuracy of 0.906. A strong correlation was revealed between MK in that region and YMRS in BD patients (r = -0.641, corrected P = 0.042) or 17-HDRS in MDD patients (r = -0.613, corrected P = 0.030). There were also strong correlations between a few other DKI indices and disease duration (r = -0.676 or 0.626, corrected P < 0.05). DATA CONCLUSION: DKI detected microstructural brain alterations in BD and MDD. Its indices may be useful to distinguish the two disorders or to reflect disease severity and duration. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.
  • Ryosuke Shimura, Toshiya Osanai, Kohsuke Kudo
    No shinkei geka. Neurological surgery 48 (4) 295 - 306 2020/04 [Refereed][Not invited]
  • Sho Furuya, Masanao Naya, Osamu Manabe, Kenji Hirata, Hiroshi Ohira, Tadao Aikawa, Kazuhiro Koyanagawa, Keiichi Magota, Ichizo Tsujino, Toshihisa Anzai, Yuji Kuge, Noriko Oyama-Manabe, Kohsuke Kudo, Tohru Shiga, Nagara Tamaki
    Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology 2019/12/09 [Refereed][Not invited]
     
    BACKGROUND: 18F-fluoromisonidazole (FMISO) is a hypoxia positron emission tomography (PET) tracer. Here, we evaluated cardiac and extra-cardiac sarcoidosis using both FMISO and 18F-fluorodeoxyglucose (FDG) PET/CT in a prospective cohort of patients with sarcoidosis. METHODS: Ten consecutive sarcoidosis patients with suspected cardiac involvement were prospectively enrolled. Each patient fasted overnight (for ≥ 18 hours) preceded by a low-carbohydrate diet before FDG PET/CT but not given special dietary instructions before the FMISO PET/CT scan. We visually and semiquantitatively assessed the uptakes of FMISO and FDG using the maximal standardized uptake value (SUVmax). The metabolic volume (MV) of FDG was calculated as the volume within the boundary determined by the threshold (mean SUV of blood pool × 1.5). RESULTS: Nine patients showed focal FDG uptake in the myocardium and were diagnosed with cardiac sarcoidosis. Among the patients with extra-cardiac lesions, FDG uptake was seen in 8 lymph nodes and 3 lung lesions. FMISO uptake was seen in the 7 cardiac (77.8%) and 6 extra-cardiac (54.5%) lesions. None of the patients showed physiological FMISO uptake in the myocardium. The SUVmax values of the lesions with FMISO uptake were higher than those of the lesions without FMISO uptake in both the cardiac (SUVmax: 9.9, IQR: 8.4-10.0 vs 7.3, IQR: 6.3-8.2) and non-cardiac lesions (SUVmax: 17.6, IQR: 14.5-19.3 vs 6.1, IQR: 5.9-6.2; P = 0.006). The MV values of the lesions with FMISO uptake were significantly higher than those of the lesions without FMISO uptake (111.3, IQR: 78.3-135.7 vs 6.4, IQR: 1.9-23.3; P = 0.0009). CONCLUSIONS: FMISO showed no physiological myocardial uptake and did not require special preparation. FMISO PET has the potential to detect hypoxic lesions in patients with sarcoidosis.
  • Kentaro Kobayashi, Osamu Manabe, Kenji Hirata, Shigeru Yamaguchi, Hiroyuki Kobayashi, Shunsuke Terasaka, Takuya Toyonaga, Sho Furuya, Keiichi Magota, Yuji Kuge, Kohsuke Kudo, Tohru Shiga, Nagara Tamaki
    European journal of nuclear medicine and molecular imaging 2019/11/28 [Refereed][Not invited]
     
    PURPOSE: 18F-fluoromisonidazole (18F-FMISO) is the most widely used positron emission tomography (PET) tracer for imaging tumor hypoxia. Previous reports suggested that the time from injection to the scan may affect the assessment of 18F-FMISO uptake. Herein, we directly compared the images at 2 h and 4 h after a single injection of 18F-FMISO. METHODS: Twenty-three patients with or suspected of having a brain tumor were scanned twice at 2 and 4 h following an intravenous injection of 18F-FMISO. We estimated the mean standardized uptake value (SUV) of the gray matter and white matter and the gray-to-white matter ratio in the background brain tissue from the two scans. We also performed a semi-quantitative analysis using the SUVmax and maximum tumor-to-normal ratio (TNR) for the tumor. RESULTS: At 2 h, the SUVmean of gray matter was significantly higher than that of white matter (median 1.23, interquartile range (IQR) 1.10-1.32 vs. 1.04, IQR 0.95-1.16, p < 0.0001), whereas at 4 h, it significantly decreased to approach that of the white matter (1.10, IQR 1.00-1.23 vs. 1.02, IQR 0.93-1.13, p = NS). The gray-to-white matter ratio thus significantly declined from 1.17 (IQR 1.14-1.19) to 1.09 (IQR 1.07-1.10) (p < 0.0001). All 7 patients with glioblastoma showed significant increases in the SUVmax (2.20, IQR 1.67-3.32 at 2 h vs. 2.65, IQR 1.74-4.41 at 4 h, p = 0.016) and the TNR (1.75, IQR 1.40-2.38 at 2 h vs. 2.34, IQR 1.67-3.60 at 4 h, p = 0.016). CONCLUSION: In the assessment of hypoxic tumors, 18F-FMISO PET for hypoxia imaging should be obtained at 4 h rather than 2 h after the injection.
  • Yukie Shimizu, Kohsuke Kudo, Hiroyuki Kameda, Taisuke Harada, Noriyuki Fujima, Takuya Toyonaga, Khin Khin Tha, Hiroki Shirato
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 1347-3182 2019/10/15 [Refereed][Not invited]
     
    PURPOSE: The aim of this study was to generate a multivariate model using various MRI markers of blood flow and vascular permeability and accumulation of 18F-fluorodeoxyglucose (FDG) to predict the extent of hypoxia in an 18F-fluoromisonidazole (FMISO)-positive region. METHODS: Fifteen patients aged 27-74 years with brain tumors (glioma, n = 13; lymphoma, n = 1; germinoma, n = 1) were included. MRI scans were performed using a 3T scanner, and dynamic contrast-enhanced (DCE) perfusion and arterial spin labeling images were obtained. Ktrans and Vp maps were generated using the DCE images. FDG and FMISO positron emission tomography scans were also obtained. A model for predicting FMISO positivity was generated on a voxel-by-voxel basis by a multivariate logistic regression model using all the MRI parameters with and without FDG. Receiver-operating characteristic curve analysis was used to detect FMISO positivity with multivariate and univariate analysis of each parameter. Cross-validation was performed using the leave-one-out method. RESULTS: The area under the curve (AUC) was highest for the multivariate prediction model with FDG (0.892) followed by the multivariate model without FDG and univariate analysis with FDG and Ktrans (0.844 for all). In cross-validation, the multivariate model with FDG had the highest AUC (0.857 ± 0.08) followed by the multivariate model without FDG (0.834 ± 0.119). CONCLUSION: A multivariate prediction model created using blood flow, vascular permeability, and glycometabolism parameters can predict the extent of hypoxia in FMISO-positive areas in patients with brain tumors.
  • Ryo Morita, Daisuke Abo, Yusuke Sakuhara, Takeshi Soyama, Norio Katoh, Naoki Miyamoto, Yuusuke Uchinami, Shinichi Shimizu, Hiroki Shirato, Kohsuke Kudo
    Minimally invasive therapy & allied technologies : MITAT : official journal of the Society for Minimally Invasive Therapy 1 - 10 1364-5706 2019/09/13 [Refereed][Not invited]
     
    Purpose: This study evaluated the success rate and complications of percutaneous implantation of hepatic fiducial true-spherical gold markers for real-time adaptive radiotherapy (RAR), which constitutes real-time image-guided radiotherapy with gating. Material and methods: We retrospectively evaluated 100 patients who underwent 116 percutaneous intrahepatic implantations of 2-mm-diameter, spherical, gold fiducial markers before RAR from 1999 to 2016, with Seldinger's method. We defined technical success as marker placement at the intended liver parenchyma, without mispositioning, and clinical success as successful tracking of the gold marker and completion of planned RAR. Complications related to marker placement were assessed. Results: The technical success rate for true-spherical gold marker implantation was 92.2% (107/116). Nine of 116 markers migrated (intra-procedurally in seven patients, delayed in two patients). Migration out of the liver (n = 4) or intrahepatic vessels (n = 5) occurred without complications; these markers were not retrieved. The clinical success rate was 100.0% (115/115). Abdominal pain occurred in 16 patients, fever and hemorrhage in seven patients each, and pneumothorax and nausea in one patient each. No major complications were encountered. Conclusions: Percutaneous transhepatic implantation of true-spherical gold markers for RAR is feasible and can be conducted with a high success rate and low complication rate.
  • Fumi Kato, Kohsuke Kudo, Hiroko Yamashita, Motoi Baba, Ai Shimizu, Noriko Oyama-Manabe, Rumiko Kinoshita, Ruijiang Li, Hiroki Shirato
    Breast cancer (Tokyo, Japan) 26 (5) 628 - 636 1340-6868 2019/09 [Refereed][Not invited]
     
    BACKGROUND: We investigated the usefulness of the minimum ADC value of primary breast lesions for predicting axillary lymph node (LN) status in luminal A-like breast cancers with clinically negative nodes in comparison with the mean ADC. METHODS: Forty-four luminal A-like breast cancers without axillary LN metastasis at preoperative clinical evaluation, surgically resected with sentinel LN biopsy, were retrospectively studied. Mean and minimum ADC values of each lesion were measured and statistically compared between LN positive (n = 12) and LN negative (n = 32) groups. An ROC curve was drawn to determine the best cutoff value to differentiate LN status. Correlations between mean and minimum ADC values and the number of metastatic axillary LNs were investigated. RESULTS: Mean and minimum ADC values of breast lesions with positive LN were significantly lower than those with negative LN (mean 839.9 ± 110.9 vs. 1022.2 ± 250.0 × 10- 6 mm2/s, p = 0.027, minimum 696.7 ± 128.0 vs. 925.0 ± 257.6 × 10- 6 mm2/s, p = 0.004). The sensitivity and NPV using the best cutoff value from ROC using both mean and minimum ADC were 100%. AUC of the minimum ADC (0.784) was higher than that of the mean ADC (0.719). Statistically significant negative correlations were observed between both mean and minimum ADCs and number of positive LNs, with stronger correlation to minimum ADC than mean ADC. CONCLUSIONS: The minimum ADC value of primary breast lesions predicts axillary LN metastasis in luminal A-like breast cancer with clinically negative nodes, with high sensitivity and high NPV.
  • Mari Miyata, Shingo Kakeda, Kohsuke Kudo, Shigeru Iwata, Yoshiya Tanaka, Yi Wang, Yukunori Korogi
    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 39 (8) 1648 - 1658 2019/08 [Refereed][Not invited]
     
    The purposes of this study are to assess the oxygen extraction fraction (OEF) changes on MRI-based quantitative susceptibility mapping (QSM) in systemic lupus erythematosus (SLE) patients and to determine whether QSM-OEF is associated with disease activity in SLE. We enrolled 42 SLE patients and 20 healthy subjects (HS) who had no pathologies on conventional brain MRI. Disease activity was assessed using SLE Disease Activity Index (SLEDAI). For the measurement of QSM-OEF, QSM data were analysed using the Perfusion Mismatch Analyzer software program. Spearman's or Pearson's correlation coefficients were calculated, and independent predictors were identified through a multiple linear regression analysis. QSM-OEF was significantly higher in SLE than that in HS (51.3 ± 10.1 vs. 40.5 ± 3.7, p < 0.001). QSM-OEF was positively correlated with SLEDAI and the presence of neuropsychiatric symptom (NPS) scores (ρ = 0.663, p < 0.001 and ρ = 0.340, p = 0.028). At multiple linear regression analysis, SLEDAI and NPS were independently associated with QSM-OEF (standardized β = 0.426, p = 0.016 and standardized β = 6.148, p = 0.029). In the SLE patients, QSM-OEF is associated with disease activity, which might predict an increased risk of stroke in SLE.
  • Noriyuki Fujima, Yukie Shimizu, Daisuke Yoshida, Satoshi Kano, Takatsugu Mizumachi, Akihiro Homma, Koichi Yasuda, Rikiya Onimaru, Osamu Sakai, Kohsuke Kudo, Hiroki Shirato
    Cancers 11 (6) 2019/06/10 [Refereed][Not invited]
     
    The purpose of this study was to determine the predictive power for treatment outcome of a machine-learning algorithm combining magnetic resonance imaging (MRI)-derived data in patients with sinonasal squamous cell carcinomas (SCCs). Thirty-six primary lesions in 36 patients were evaluated. Quantitative morphological parameters and intratumoral characteristics from T2-weighted images, tumor perfusion parameters from arterial spin labeling (ASL) and tumor diffusion parameters of five diffusion models from multi-b-value diffusion-weighted imaging (DWI) were obtained. Machine learning by a non-linear support vector machine (SVM) was used to construct the best diagnostic algorithm for the prediction of local control and failure. The diagnostic accuracy was evaluated using a 9-fold cross-validation scheme, dividing patients into training and validation sets. Classification criteria for the division of local control and failure in nine training sets could be constructed with a mean sensitivity of 0.98, specificity of 0.91, positive predictive value (PPV) of 0.94, negative predictive value (NPV) of 0.97, and accuracy of 0.96. The nine validation data sets showed a mean sensitivity of 1.0, specificity of 0.82, PPV of 0.86, NPV of 1.0, and accuracy of 0.92. In conclusion, a machine-learning algorithm using various MR imaging-derived data can be helpful for the prediction of treatment outcomes in patients with sinonasal SCCs.
  • Kaori Endo, Masahiko Takahata, Hiroyuki Sugimori, Satoshi Yamada, Shigeru Tadano, Jeffrey Wang, Masahiro Todoh, Yoichi M Ito, Daisuke Takahashi, Kohsuke Kudo, Norimasa Iwasaki
    Clinical biomechanics (Bristol, Avon) 65 13 - 18 0268-0033 2019/05 [Refereed][Not invited]
     
    BACKGROUND: Since bone mass is not the only determinant of bone strength, there has been increasing interest in incorporating the bone quality into fracture risk assessments. We aimed to examine whether the magnetic resonance imaging (MRI) T1 or T2 mapping value could provide information that is complementary to bone mineral density for more accurate prediction of cancellous bone strength. METHODS: Four postmenopausal women with hip osteoarthritis underwent 3.0-T MRI to acquire the T1 and T2 values of the cancellous bone of the femoral head before total hip arthroplasty. After the surgery, the excised femoral head was portioned into multiple cubic cancellous bone specimens with side of 5 mm, and the specimens were then subjected to microcomputed tomography followed by biomechanical testing. FINDINGS: The T1 value positively correlated with the yield stress (σy) and collapsed stress (σc). The T2 value did not correlate with the yield stress, but it correlated with the collapsed stress and strength reduction ratio (σc/σy), which reflects the progressive re-fracture risk. Partial correlation coefficient analyses, after adjusting for the bone mineral density, showed a statistically significant correlation between T1 value and yield stress. The use of multiple coefficients of determination by least squares analysis emphasizes the superiority of combining the bone mineral density and the MRI mapping values in predicting the cancellous bone strength compared with the bone mineral density-based prediction alone. INTERPRETATION: The MRI T1 and T2 values predict cancellous bone strength including the change in bone quality.
  • Suzuko Aoike, Hiroyuki Sugimori, Noriyuki Fujima, Yuriko Suzuki, Yukie Shimizu, Akira Suwa, Kinya Ishizaka, Kohsuke Kudo
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 18 (2) 170 - 177 1347-3182 2019/04/10 [Refereed][Not invited]
     
    We evaluated 3D pseudo-continuous arterial spin labeling (pCASL) using turbo spin echo with a pseudo-steady-state (PSS) readout in comparison with the other major readout methods of 3D spiral and 2D echo-planar imaging (EPI). 3D-PSS produced cerebral blood flow (CBF) values well correlated to those of the 3D spiral readout. By visual evaluation, the image quality of 3D-PSS pCASL was superior to that of 2D-EPI. The 3D-PSS technique was suggested useful as pCASL readout.
  • Yasuka Kikuchi, Masanao Naya, Noriko Oyama-Manabe, Osamu Manabe, Hiroyuki Sugimori, Kohsuke Kudo, Fumi Kato, Tadao Aikawa, Hiroyuki Tsutsui, Nagara Tamaki, Hiroki Shirato
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 18 (2) 134 - 141 1347-3182 2019/04/10 [Refereed][Not invited]
     
    PURPOSE: The aim of this study was to verify coronary flow velocity reserve (CFVR) on the left main trunk (LMT) in comparison with myocardial flow reserve (MFR) by 15O-labeled water positron emission tomography (PET) (MFR-PET) in both the healthy adults and the patients with coronary artery disease (CAD), and to evaluate the feasibility of CFVR to detect CAD. METHODS: Eighteen healthy adults and 13 patients with CAD were evaluated. CFVR in LMT was estimated by 3T magnetic resonance imaging (MRI) with phase contrast technique. MFR-PET in the LMT territory including anterior descending artery and circumflex artery was calculated as the ratio of myocardial blood flow (MBF)-PET at stress to MBF-PET at rest. RESULTS: There was a significant positive relationship between CFVR and MFR-PET (R = 0.45, P < 0.0001). Inter-observer calculations of CFVR showed good correlation (R2 = 0.93, P < 0.0001). The CFVR in patients with CAD was significantly lower than that in healthy adults (1.90 ± 0.61 vs. 2.77 ± 1.03, respectively, P = 0.01), which were similar to the results of MFR-PET (2.23 ± 0.84 vs. 3.96 ± 1.04, respectively, P < 0.0001). For the detection of patients with CAD, the area under the curve was 0.78 (P = 0.01). The sensitivity was 0.77 and specificity was 0.72 when a cut-off of 2.15 was used. CONCLUSION: CFVR by 3T was validated with MFR-PET. CFVR could detect the patients with CAD. This method is a simple and reliable index without radiation or contrast material.
  • 背部刺傷の1例
    曽山 武士, 阿保 大介, 森田 亮, 吉野 裕紀, 木村 輔, 工藤 與亮, 前川 邦彦, 新垣 雅人, 長津 明久, 若山 顕治
    日本インターベンショナルラジオロジー学会雑誌 (一社)日本インターベンショナルラジオロジー学会 33 (4) 423 - 423 1340-4520 2019/04 [Refereed][Not invited]
  • Fujima Noriyuki, Homma Akihiro, Harada Taisuke, Shimizu Yukie, Tha Khin Khin, Kano Satoshi, Mizumachi Takatsugu, Li Ruijiang, Kudo Kohsuke, Shirato Hiroki
    CANCER IMAGING 19 1470-7330 2019/02/04 [Refereed][Not invited]
  • Noriyuki Fujima, Akihiro Homma, Taisuke Harada, Yukie Shimizu, Khin Khin Tha, Satoshi Kano, Takatsugu Mizumachi, Ruijiang Li, Kohsuke Kudo, Hiroki Shirato
    Cancer imaging : the official publication of the International Cancer Imaging Society 19 (1) 5 - 5 1740-5025 2019/02/04 [Refereed][Not invited]
     
    BACKGROUND: To assess the utility of histogram and texture analysis of magnetic resonance (MR) fat-suppressed T2-weighted imaging (Fs-T2WI) for the prediction of histological diagnosis of head and neck squamous cell carcinoma (SCC) and malignant lymphoma (ML). METHODS: The cases of 57 patients with SCC (45 well/moderately and 12 poorly differentiated SCC) and 10 patients with ML were retrospectively analyzed. Quantitative parameters with histogram features (relative mean signal, coefficient of variation, kurtosis and skewness) and gray-level co-occurrence matrix (GLCM) features (contrast, correlation, energy and homogeneity) were calculated using Fs-T2WI data with a manual tumor region of interest (ROI). RESULTS: The following significantly different values were obtained for the total SCC versus ML groups: relative mean signal (3.65 ± 0.86 vs. 2.61 ± 0.49), contrast (72.9 ± 16.2 vs. 49.3 ± 8.7) and homogeneity (2.22 ± 0.25 × 10- 1 vs. 2.53 ± 0.12 × 10- 1). In the comparison of the SCC histological grades, the relative mean signal and contrast were significantly lower in the poorly differentiated SCC (2.89 ± 0.63, 56.2 ± 12.9) compared to the well/moderately SCC (3.85 ± 0.81, 77.5 ± 13.9). The homogeneity in poorly differentiated SCC (2.56 ± 0.15 × 10- 1) was higher than that of the well/moderately SCC (2.1 ± 0.18 × 10- 1). CONCLUSIONS: Parameters obtained by histogram and texture analysis of Fs-T2WI may be useful for noninvasive prediction of histological type and grade in head and neck malignancy.
  • Masahiro Yasaka, Kazuo Minematsu, Kazunori Toyoda, Etsuro Mori, Teruyuki Hirano, Toshimitsu Hamasaki, Hiroshi Yamagami, Takehiko Nagao, Shinichi Yoshimura, Shinichiro Uchiyama, Takenori Yamaguchi, Yasushi Okada, Satoshi Okuda, Kazumi Kimura, Norio Tanahashi, Yasuo Terayama, Yoichiro Hashimoto, Yasuhiro Hasegawa, Kiyohiro Houkin, Masayasu Matsumoto, Kazuo Kitagawa, Masahiro Yasaka, Ken Nagata, Shigeru Nogawa, Yoshiaki Kumon, Takeshi Kimura, Yutaka Furukawa, Tomohiro Sakamoto, Makoto Sakai, Kohsuke Kudo, Toshinori Hirai, Shotai Kobayashi
    PLOS ONE 14 (2) 1932-6203 2019/02 [Refereed][Not invited]
     
    The efficacy of early anticoagulation in acute stroke with nonvalvular atrial fibrillation (NVAF) remains unclear. We performed a study to evaluate the risk of recurrent ischemic stroke (IS) and major bleeding in acute IS patients with NVAF who started rivaroxaban. This observational study evaluated patients with NVAF and acute IS/transient ischemic attack (TIA) in the middle cerebral arterial territory who started rivaroxaban within 30 days after the index IS/TIA. The primary endpoints were recurrent IS and major bleeding within 90 days after the index IS/TIA. The relationship between the endpoints and the time to start rivaroxaban was evaluated by correlation analysis using cerebral infarct volume, determined by diffusion-weighted magnetic resonance images within 48 hours of onset of the index IS/TIA. Of 1309 patients analyzed, recurrent IS occurred in 30 (2.3%) and major bleeding in 11 (0.8%) patients. Among patients with known infarct size (N = 1207), those with small (<4.0 cm(3)), medium (>= 4.0 and <22.5 cm(3)), and large (>= 22.5 cm(3)) infarcts started rivaroxaban a median of 2.9, 2.9, and 5.8 days, respectively, after the index IS/TIA. Recurrent IS was significantly less frequent when starting rivaroxaban <= 14 days versus >= 15 days after IS (2.0% versus 6.8%, P=0.0034). Incidences of recurrent IS and major bleeding in whom rivaroxaban was started <3 days (N = 584) after IS were also low: 1.5% and 0.7%, respectively. Initiation of rivaroxaban administration in acute IS or TIA was associated with a low recurrence of IS (2.3%), and a low incidence of major bleeding events (0.8%) for 90 days after the index stroke. For the prevention of recurrent attacks in acute IS patients with NVAF, it is feasible to start the administration of rivaroxaban within 14 days of onset. Rivaroxaban started within 3 days of onset may be a feasible treatment option for patients with a small or medium-sized infarction.
  • Oyama-Manabe Noriko, Manabe Osamu, Naya Masanao, Kudo Kohsuke, Tamaki Nagara
    Annals of Nuclear Cardiology 日本心臓核医学会 5 (1) 79 - 83 2189-3926 2019 [Refereed][Not invited]
     
    Cardiac computed tomography (CT) could provide the comprehensive morphologic and functional information of coronary artery disease. Coronary CT angiography has been well established for identification and management of symptomatic patients with or suspected coronary artery disease. However, we should know the anatomical stenosis is not the same as the functional one needed to be treated. Dynamic perfusion imaging could lead a non-invasive quantitative evaluation of myocardial ischemia with estimation of myocardial blood flow. In this review, we address the characteristics and advantages of cardiac CT, in particular dynamic perfusion CT for quantitative evaluation of myocardial ischemia.
  • N Fujima, K Hirata, T Shiga, R Li, K Yasuda, R Onimaru, K Tsuchiya, S Kano, T Mizumachi, A Homma, K Kudo, H Shirato
    Clinical radiology 73 (12) 1059.e1-1059.e8  2018/12 [Refereed][Not invited]
     
    AIM: To assess potential prognostic factors in pharynx squamous cell carcinoma (SCC) patients by quantitative morphological and intratumoural characteristics obtained by 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (FDG-PET/CT). MATERIALS AND METHODS: The cases of 54 patients with pharynx SCC who underwent chemoradiation therapy were analysed retrospectively. Using their FDG-PET data, the quantitative morphological and intratumoural characteristics of 14 parameters were calculated. The progression-free survival (PFS) and overall survival (OS) information was obtained from patient medical records. Univariate and multivariate analyses were performed to assess the 14 quantitative parameters as well as the T-stage, N-stage, and tumour location data for their relation to PFS and OS. When an independent predictor was suggested in the multivariate analysis, the parameter was further assessed using the Kaplan-Meier method. RESULTS: In the assessment of PFS, the univariate and multivariate analyses indicated the following as independent predictors: the texture parameter of homogeneity and the morphological parameter of sphericity. In the Kaplan-Meier analysis, the PFS rate was significantly improved in the patients who had both a higher value of homogeneity (p=0.01) and a higher value of sphericity (p=0.002). With the combined use of homogeneity and sphericity, the patients with different PFS rates could be divided more clearly. CONCLUSION: The quantitative parameters of homogeneity and sphericity obtained by FDG-PET can be useful for the prediction of the PFS of pharynx SCC patients, especially when used in combination.
  • Taisuke Harada, Kohsuke Kudo
    Brain and nerve = Shinkei kenkyu no shinpo 70 (12) 1331 - 1340 1881-6096 2018/12 [Refereed][Not invited]
     
    Tremor is one of the common movement disorders encountered in a clinical practice. Tremor is often difficult to diagnose and can be easily mistaken for another disorder, hence diagnostic imaging is employed to provide objective information. The morphometry, signal changes, neuromelanin, and iron deposition can be evaluated by MRI, whereas cardiac sympathetic nerve and dopamine transporter degeneration are detected by means of nuclear medicine. The purpose of this article is to provide an overview of the role and indications of imaging test, as well as a review of the methods in which the findings of images are interpreted.
  • Oyama-Manabe Noriko, Satoshi Yabusaki, Manabe Osamu, Kato Fumi, Kanno-Okada Hiromi, Kudo Kohsuke
    RADIOGRAPHICS 38 (7) 1934 - 1948 0271-5333 2018/11 [Refereed][Not invited]
  • Noriyuki Fujima, Kenji Hirata, Tohru Shiga, Koichi Yasuda, Rikiya Onimaru, Kazuhiko Tsuchiya, Satoshi Kano, Takatsugu Mizumachi, Akihiro Homma, Kohsuke Kudo, Hiroki Shirato
    Quantitative imaging in medicine and surgery 8 (8) 788 - 795 2223-4292 2018/09 [Refereed][Not invited]
     
    Background: To investigate the utility of quantitative morphological and intratumoral characteristics obtained by 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (FDG-PET/CT) for the prediction of treatment outcome in patients with nasal or paranasal cavity squamous cell carcinoma (SCC). Methods: Twenty-four patients with nasal or paranasal cavity SCC who received curative non-surgical therapy (a combination of super-selective arterial cisplatin infusion and radiotherapy) were retrospectively analyzed. From pre-treatment FDG-PET data, a total of 13 parameters of quantitative morphological characteristics (tumor volume, surface area and sphericity), intratumoral characteristics (the maximum and mean standard uptake value, three intratumoral histogram and four textural parameters) and total lesion glycolysis (TLG) were respectively calculated. Information regarding the treatment outcome was determined from the histological diagnosis or clinical follow-up. Each of the 13 quantitative parameters as well as T- and N-stage was assessed for its relation to treatment outcome of local control or failure. Results: In univariate analysis, significant differences in surface area and sphericity between the local control and failure groups were observed. The receiver operating characteristic (ROC) curve analysis showed that sphericity had the highest accuracy of 0.88. In the multivariate analysis, sphericity was revealed as an independent predictor of the local control or failure. Conclusions: The quantitative parameters of sphericity are useful to predict the treatment outcome in patients with nasal or paranasal SCC.
  • Kohsuke Kudo, Taisuke Harada, Hiroyuki Kameda, Ikuko Uwano, Fumio Yamashita, Satomi Higuchi, Kunihiro Yoshioka, Makoto Sasaki
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 17 (3) 223 - 230 1347-3182 2018/07/10 [Refereed][Not invited]
     
    PURPOSE: The feasibility of steady-state sequences for 17O imaging was evaluated based on a kinetic analysis of the brain parenchyma and cerebrospinal fluid (CSF). MATERIALS AND METHODS: The institutional review board approved this prospective study with written informed consent. Dynamic 2D or 3D steady-state sequences were performed in five and nine participants, respectively, with different parameters using a 3T scanner. During two consecutive dynamic scans, saline was intravenously administered for control purposes in the first scan, and 20% 17O-labeled water (1 mL/Kg) was administered in the second scan. Signal changes relative to the baseline were calculated, and kinetic analyses of the curves were conducted for all voxels. Region of interest analysis was performed in the brain parenchyma, choroid plexus, and CSF spaces. RESULTS: Average signal drops were significantly larger in the 17O group than in the controls for most of the imaging parameters. Different kinetic parameters were observed between the brain parenchyma and CSF spaces. Average and maximum signal drops were significantly larger in the CSF spaces and choroid plexus than in the brain parenchyma. Bolus arrival, time to peak, and the first moment of dynamic curves of 17O in the CSF space were delayed compared to that in the brain parenchyma. Significant differences between the ventricle and subarachnoid space were also noted. CONCLUSION: Steady-state sequences are feasible for indirect 17O imaging with reasonable temporal resolution; this result is potentially important for the analysis of water kinetics and aquaporin function for several disorders.
  • Hiroyuki Kameda, Kohsuke Kudo, Tsuyoshi Matsuda, Taisuke Harada, Yuji Iwadate, Ikuko Uwano, Fumio Yamashita, Kunihiro Yoshioka, Makoto Sasaki, Hiroki Shirato
    Journal of magnetic resonance imaging : JMRI 48 (1) 94 - 101 1053-1807 2018/07 [Refereed][Not invited]
     
    BACKGROUND: Respiration-induced phase shift affects B0 /B1+ mapping repeatability in parallel transmission (pTx) calibration for 7T brain MRI, but is improved by breath-holding (BH). However, BH cannot be applied during long scans. PURPOSE: To examine whether interleaved acquisition during calibration scanning could improve pTx repeatability and image homogeneity. STUDY TYPE: Prospective. SUBJECTS: Nine healthy subjects. FIELD STRENGTH/SEQUENCE: 7T MRI with a two-channel RF transmission system was used. ASSESSMENT: Calibration scanning for B0 /B1+ mapping was performed under sequential acquisition/free-breathing (Seq-FB), Seq-BH, and interleaved acquisition/FB (Int-FB) conditions. The B0 map was calculated with two echo times, and the B1+ map was obtained using the Bloch-Siegert method. Actual flip-angle imaging (AFI) and gradient echo (GRE) imaging were performed using pTx and quadrature-Tx (qTx). All scans were acquired in five sessions. Repeatability was evaluated using intersession standard deviation (SD) or coefficient of variance (CV), and in-plane homogeneity was evaluated using in-plane CV. STATISTICAL TESTS: A paired t-test with Bonferroni correction for multiple comparisons was used. RESULTS: The intersession CV/SDs for the B0 /B1+ maps were significantly smaller in Int-FB than in Seq-FB (Bonferroni-corrected P < 0.05 for all). The intersession CVs for the AFI and GRE images were also significantly smaller in Int-FB, Seq-BH, and qTx than in Seq-FB (Bonferroni-corrected P < 0.05 for all). The in-plane CVs for the AFI and GRE images in Seq-FB, Int-FB, and Seq-BH were significantly smaller than in qTx (Bonferroni-corrected P < 0.01 for all). DATA CONCLUSION: Using interleaved acquisition during calibration scans of pTx for 7T brain MRI improved the repeatability of B0 /B1+ mapping, AFI, and GRE images, without BH. LEVEL OF EVIDENCE: 1 Technical Efficacy Stage 1 J. Magn. Reson. Imaging 2017.
  • Morita Ryo, Abo Daisuke, Soyama Takeshi, Sakuhara Yusuke, Kajiyama Masayoshi, Kudo Kohsuke
    Interventional Radiology 3 (2) 88 - 92 2018/06 [Refereed][Not invited]
     
    症例は50歳女性で、他院で敗血症、播種性血管内凝固症候群および急性肝機能不全と診断され、2週間保存療法が施行されていた。しかし、退院後、急性で重度の背部痛と左側腹痛を呈し、CTでは肝動脈に多発性紡錘状動脈瘤が認められ、当院に救急搬送された。臨床所見では血行動力学的に安定していたため、動脈瘤破裂リスクを低減させるため、降圧療法を施行した。入院3日目のフォローアップCT検査により、動脈瘤に進行性の血栓形成が認められ、その後の臨床経過と画像所見から、分節性動脈中膜融解症(SAM)と確定診断された。入院から48日目には腹痛は完全に改善され、動脈瘤破裂リスクも低いと判断されたため退院となった。退院から6ヵ月後の造影CTでは、多発肝動脈瘤の完治と開存した正常肝動脈分枝が確認され、退院から1年後のフォローアップCT検査でも、同様の所見が得られた。
  • Daichi Nakagawa, Kohsuke Kudo, Olatilewa Awe, Mario Zanaty, Yasunori Nagahama, Cameron Cushing, Vincent Magnotta, Minako Hayakawa, Lauren Allan, Jeremy Greenlee, Issam A Awad, Timothy Carroll, James Torner, Madhavan L Raghavan, David M Hasan
    Journal of neurosurgery 130 (4) 1 - 7 0022-3085 2018/05/01 [Refereed][Not invited]
     
    OBJECTSentinel headaches (SHs) associated with cerebral aneurysms (CAs) could be due to microbleeds, which are considered a sign that an aneurysm is unstable. Despite the prognostic importance of these microbleeds, they remain difficult to detect using routine imaging studies. The objective of this pilot study is to detect microbleeds associated with SH using a magnetic resonance imaging (MRI) quantitative susceptibility mapping (QSM) sequence and then evaluate the morphological characteristics of unstable aneurysms with microbleeds.METHODSTwenty CAs in 16 consecutive patients with an initial presentation of headache (HA) leading to a diagnosis of CA were analyzed. Headaches in 4 of the patients (two of whom had 2 aneurysms each) met the typical definition of SH, and the other 12 patients (two of whom also had 2 aneurysms each) all had migraine HA. All patients underwent imaging with the MRI-QSM sequence. Two independent MRI experts who were blinded to the patients' clinical history performed 3D graphical analysis to evaluate for potential microbleeds associated with these CAs. Computational flow and morphometric analyses were also performed to estimate wall shear and morphological variables.RESULTSIn the 4 patients with SH, MRI-QSM results were positive for 4 aneurysms, and hence these aneurysms were considered positive for non-heme ferric iron (microbleeds). The other 16 aneurysms were negative. Among aneurysm shape indices, the undulation index was significantly higher in the QSM-positive group than in the QSM-negative group. In addition, the spatial averaged wall shear magnitude was lower in the aneurysm wall in direct contact with microbleeds.CONCLUSIONSMRI-QSM allows for objective detection of microbleeds associated with SH and therefore identification of unstable CAs. CAs with slightly greater undulation indices are associated with positive MRI-QSM results and hence with microbleeds. Studies with larger populations are needed to confirm these preliminary findings.
  • Kohsuke Kudo, Taisuke Harada, Hiroyuki Kameda, Ikuko Uwano, Fumio Yamashita, Satomi Higuchi, Kunihiro Yoshioka, Makoto Sasaki
    Journal of magnetic resonance imaging : JMRI 47 (5) 1373 - 1379 1053-1807 2018/05 [Refereed][Not invited]
     
    BACKGROUND: Few studies have been reported for T2 -weighted indirect 17 O imaging. PURPOSE/HYPOTHESIS: To evaluate the feasibility of steady-state sequences for indirect 17 O brain imaging. STUDY TYPE: Signal simulation, phantom measurements, and prospective animal experiments were performed in accordance with the institutional guidelines for animal experiments. POPULATION/SUBJECTS/PHANTOM/SPECIMEN/ANIMAL MODEL: Signal simulations of balanced steady-state free precession (bSSFP) were performed for concentrations of 17 O ranging from 0.037-1.600%. Phantom measurements with concentrations of 17 O water ranging from 0.037-1.566% were also conducted. Six healthy beagle dogs were scanned with intravenous administration of 20% 17 O-labeled water (1 mL/kg). FIELD STRENGTH/SEQUENCE: Dynamic 3D-bSSFP scans were performed at 3T MRI. 17 O-labeled water was injected 60 seconds after the scan start, and the total scan duration was 5 minutes. ASSESSMENT: Based on the result of signal simulation and phantom measurement, signal changes in the beagle dogs were measured and converted into 17 O concentrations. STATISTICAL TESTS: The 17 O concentrations were averaged for every 15 seconds, and compared to the baseline (30-45 sec) with Dunnett's multiple comparison tests. RESULTS: Signal simulation revealed that the relationships between 17 O concentration and the natural logarithm of relative signals were linear. The intraclass correlation coefficient between relative signals in phantom measurement and signal simulations was 0.974. In the animal experiments, significant increases in 17 O concentration (P < 0.05) were observed 60 seconds after the injection of 17 O. At the end of scanning, mean respective 17 O concentrations of 0.084 ± 0.026%, 0.117 ± 0.038, 0.082 ± 0.037%, and 0.049 ± 0.004% were noted for the cerebral cortex, cerebellar cortex, cerebral white matter, and ventricle. DATA CONCLUSION: Dynamic steady-state sequences were feasible for indirect 17 O imaging, and absolute quantification was possible. This method can be applied for the measurement of permeability and blood flow in the brain, and for kinetic analysis of cerebrospinal fluid. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1373-1379.
  • Kiyohiro Houkin, Hideo Shichinohe, Koji Abe, Teruyo Arato, Mari Dezawa, Osamu Honmou, Nobutaka Horie, Yasuo Katayama, Kohsuke Kudo, Satoshi Kuroda, Tomohiro Matsuyama, Ichiro Miyai, Izumi Nagata, Kuniyasu Niizuma, Ken Sakushima, Masanori Sasaki, Norihiro Sato, Kenji Sawanobori, Satoshi Suda, Akihiko Taguchi, Teiji Tominaga, Haruko Yamamoto, Toru Yamashita, Toshiki Yoshimine
    Stroke 49 (4) e145-e152 - + 0039-2499 2018/04 [Refereed][Not invited]
  • Keita Sakamoto, Noriko Oyama-Manabe, Osamu Manabe, Tadao Aikawa, Yasuka Kikuchi, Harue Sasai-Masuko, Masanao Naya, Kohsuke Kudo, Fumi Kato, Nagara Tamaki, Hiroki Shirato
    Japanese journal of radiology 36 (2) 103 - 112 1867-1071 2018/02 [Refereed][Not invited]
     
    PURPOSE: To evaluate heterogeneity of myocardial contraction in relation to extensive late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) patients with preserved left ventricular ejection fraction, using fast strain-encoded magnetic resonance imaging. MATERIALS AND METHODS: Twenty-two HCM patients and 24 age-matched control subjects were included in this retrospective study. The regional and global peak values of longitudinal and circumferential strain (LSregional, LSglobal, CSregional, CSglobal), and their regional heterogeneities were evaluated using coefficients of variation (LSCoV, CSCoV) in relation to LGE. Receiver operating characteristic curve analysis was performed to identify patients with a total left ventricular myocardial LGE ≥ 15%. RESULTS: LSglobal in HCM patients was significantly decreased compared to that in controls (- 14.4 ± 2.4% vs - 17.2 ± 2.0%; p = 0.0004), while CSglobal was not (p = 1.0). Negative LGE segments demonstrated decreased LSregional in HCM patients compared to in controls (p < 0.0001), while CSregional was not decreased. CSCoV demonstrated the largest area under the curve (AUC) (0.91), with high sensitivity (83%) and specificity (94%) for detection of HCM patients with extensive LGE, while the AUC of LSCoV was low (0.49). CONCLUSION: The heterogeneity in CSregional has a high diagnostic value for detection of HCM patients with extensive LGE.
  • Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Daisuke Yoshida, Kohsuke Kudo, Hiroki Shirato
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 17 (1) 21 - 27 1347-3182 2018/01/10 [Refereed][Not invited]
     
    PURPOSE: To evaluate the diagnostic power of hybrid intravoxel incoherent motion (IVIM)-diffusion kurtosis imaging (DKI) model parameters in pretreatment for the prediction of future distant metastasis in head and neck squamous cell carcinoma (HNSCC) patients. MATERIALS AND METHODS: We retrospectively evaluated 49 HNSCC patients who underwent curative chemoradiation therapy. Diffusion-weighted image (DWI) acquired by single-shot spin-echo echo-planar imaging with 12 b-values (0-2000) was performed in all patients before any treatment. We calculated the IVIM-DKI parameters and the conventional apparent diffusion coefficient (ADC) in the ROI placed on the primary lesion. The presence of future distant metastasis was determined by histological findings or clinical follow-up. RESULTS: A univariate analysis revealed significant differences between the patients with distant metastasis and those without in slow diffusion coefficient (D) and kurtosis value (K). Highest diagnostic accuracy was obtained by the D value. In addition, a multivariate analysis revealed that the D value was an independent predictor of future distant metastasis. CONCLUSION: The D and K values obtained by this hybrid IVIM-DKI model can be one of the diagnostic tools for the prediction of future distant metastasis in HNSCC patients.
  • Kinya Ishizaka, Kohsuke Kudo, Kuniaki Harada, Toru Shirai, Taro Fujiwara, Suzuko Aoike, Sayaka Takamori, Hiroki Shirato
    Journal of magnetic resonance imaging : JMRI 47 (1) 123 - 130 1053-1807 2018/01 [Refereed][Not invited]
     
    PURPOSE: To evaluate the homogeneity of the radiofrequency magnetic field (B1+ ) and signal intensity using different arm positions during 3T thoracolumbar spinal imaging. MATERIALS AND METHODS: Twenty volunteers were scanned with a four-channel radiofrequency (RF) transmit coil at 3T, with arms on the bed (conventional), arms elevated by 100 mm (arm lift), or with the arms-up position (elevated arm). Axial B1+ maps and sagittal T1 -weighted image (T1 WI)-performed RF shimming were obtained for each arm position. The mean and standard deviation (SD) of the flip angle (FA) at the center of the vertebra on each B1+ map, and contrast noise ratios (CNRs) between the spinal cord and cerebrospinal fluid of sagittal T1 WI, were calculated and compared among the different arm positions. RESULTS: Mean FA values (degrees) for the arm lift and elevated arm positions were significantly larger than for the conventional position (P < 0.001 for both) at the twelfth thoracic vertebra (Th12). FA SD values for the arm lift and elevated arm position were significantly smaller than for the conventional position (P < 0.001 for both) at Th12. CNR for the arm lift and elevated arm position were significantly higher than for the conventional position (P = 0.007 and 0.002, respectively). The mean and SD of the FA and the CNR did not differ significantly for the arm lift and elevated arm positions (P = 0.591, 0.958, and 0.927, respectively). CONCLUSION: Inhomogeneities of B1+ and signal intensities were improved by simply changing the arm position in 3T thoracolumbar spinal imaging. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:123-130.
  • Khin Khin Tha, Ulrich Katscher, Shigeru Yamaguchi, Christian Stehning, Shunsuke Terasaka, Noriyuki Fujima, Kohsuke Kudo, Ken Kazumata, Toru Yamamoto, Marc Van Cauteren, Hiroki Shirato
    European radiology 28 (1) 348 - 355 0938-7994 2018/01 [Refereed][Not invited]
     
    OBJECTIVES: This study noninvasively examined the electrical conductivity (σ) characteristics of diffuse gliomas using MRI and tested its validity. METHODS: MRI including a 3D steady-state free precession (3D SSFP) sequence was performed on 30 glioma patients. The σ maps were reconstructed from the phase images of the 3D SSFP sequence. The σ histogram metrics were extracted and compared among the contrast-enhanced (CET) and noncontrast-enhanced tumour components (NCET) and normal brain parenchyma (NP). Difference in tumour σ histogram metrics among tumour grades and correlation of σ metrics with tumour grades were tested. Validity of σ measurement using this technique was tested by correlating the mean tumour σ values measured using MRI with those measured ex vivo using a dielectric probe. RESULTS: Several σ histogram metrics of CET and NCET of diffuse gliomas were significantly higher than NP (Bonferroni-corrected p ≤ .045). The maximum σ of NCET showed a moderate positive correlation with tumour grade (r = .571, Bonferroni-corrected p = .018). The mean tumour σ measured using MRI showed a moderate positive correlation with the σ measured ex vivo (r = .518, p = .040). CONCLUSIONS: Tissue σ can be evaluated using MRI, incorporation of which may better characterise diffuse gliomas. KEY POINTS: • This study tested the validity of noninvasive electrical conductivity measurements by MRI. • This study also evaluated the electrical conductivity characteristics of diffuse glioma. • Gliomas have higher electrical conductivity values than the normal brain parenchyma. • Noninvasive electrical conductivity measurement can be helpful for better characterisation of glioma.
  • J-I. Nomura, I. Uwano, M. Sasaki, K. Kudo, F. Yamashita, K. Ito, S. Fujiwara, M. Kobayashi, K. Ogasawara
    AMERICAN JOURNAL OF NEURORADIOLOGY 38 (12) 2327 - 2333 0195-6108 2017/12 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Preoperative hemodynamic impairment in the affected cerebral hemisphere is associated with the development of cerebral hyperperfusion following carotid endarterectomy. Cerebral oxygen extraction fraction images generated from 7T MR quantitative susceptibility mapping correlate with oxygen extraction fraction images on positron-emission tomography. The present study aimed to determine whether preoperative oxygen extraction fraction imaging generated from 7T MR quantitative susceptibility mapping could identify patients at risk for cerebral hyperperfusion following carotid endarterectomy. MATERIALS AND METHODS: Seventy-seven patients with unilateral internal carotid artery stenosis (70%) underwent preoperative 3D T2*-weighted imaging using a multiple dipole-inversion algorithm with a 7T MR imager. Quantitative susceptibility mapping images were then obtained, and oxygen extraction fraction maps were generated. Quantitative brain perfusion single-photon emission CT was also performed before and immediately after carotid endarterectomy. ROIs were automatically placed in the bilateral middle cerebral artery territories in all images using a 3D stereotactic ROI template, and affected-to-contralateral ratios in the ROIs were calculated on quantitative susceptibility mapping-oxygen extraction fraction images. RESULTS: Ten patients (13%) showed post-carotid endarterectomy hyperperfusion (cerebral blood flow increases of 100% compared with preoperative values in the ROIs on brain perfusion SPECT). Multivariate analysis showed that a high quantitative susceptibility mapping-oxygen extraction fraction ratio was significantly associated with the development of post-carotid endarterectomy hyperperfusion (95% confidence interval, 33.5-249.7; P = .002). Sensitivity, specificity, and positive- and negative-predictive values of the quantitative susceptibility mapping-oxygen extraction fraction ratio for the prediction of the development of post-carotid endarterectomy hyperperfusion were 90%, 84%, 45%, and 98%, respectively. CONCLUSIONS: Preoperative oxygen extraction fraction imaging generated from 7T MR quantitative susceptibility mapping identifies patients at risk for cerebral hyperperfusion following carotid endarterectomy.
  • Satoshi Yabusaki, Noriko Oyama-Manabe, Osamu Manabe, Kenji Hirata, Fumi Kato, Noriyuki Miyamoto, Yoshihiro Matsuno, Kohsuke Kudo, Nagara Tamaki, Hiroki Shirato
    EJNMMI research 7 (1) 20 - 20 2191-219X 2017/12 [Refereed][Not invited]
     
    BACKGROUND: We aimed to assess the positivity, distribution, quantitative degree of vessel inflammation, and clinical characteristics of IgG4-related aortitis/periarteritis and periarteritis (IgG4-aortitis), and to examine the difference in these characteristics between cases with and without IgG4-aortitis, using fluorodeoxyglucose positron-emission tomography/computed tomography (FDG-PET/CT) co-registered with contrast-enhanced CT (CECT). We retrospectively evaluated 37 patients with IgG4-related disease (IgG4-RD) who underwent both FDG-PET/CT and CECT. The arterial SUVmax and its value normalized to the background venous blood pool (BP)-the target-to-background ratio (TBR) in the entire aorta and the major first branches-were measured. Active vascular inflammation was considered in cases with a higher FDG uptake than BP and a thickened arterial wall (>2 mm). RESULTS: Fifteen (41%) patients exhibited IgG4-aortitis. Most patients (80%) showed multiple region involvement. The entire aorta, including the major first branches, were involved, typically showing a thickened wall and high FDG uptakes. The most common site was the iliac arteries (35%), followed by the infrarenal abdominal aorta (33%), thoracic aorta (8%), first branches of the thoracic aorta (8%), suprarenal abdominal aorta (6%), and the first branches of the abdominal aorta (5%). The IgG4-aortitis-positive vessel regions were thickened, with an average maximal wall thickness of 6.3 ± 2.9 mm. The SUVmax and TBR values were significantly higher in the IgG4-aortitis-positive regions (median 3.7 [1.6-5.5] and 2.1 [1.4-3.7], respectively) than in the IgG4-aortitis-negative regions (median 2.1 [1.2-3.7] and 1.3 [0.9-2.3], respectively; p < 0.0001). The IgG4-aortitis-positive group patients were older (69.5 ± 6.0 vs. 63.3 ± 12.6 years, respectively) and had a higher male predominance (80 vs. 55%, respectively) than the negative group, although the differences were not significant (p = 0.17 and p = 0.06, respectively). CONCLUSIONS: We investigated the image characteristics of IgG4-aortitis. The entire aorta and major branches can be involved with more than 2-fold higher FDG uptake than the venous background pool, and with wall thickening. The most common involved site is the iliac arteries, followed by the infrarenal abdominal aorta.
  • 術前7 Tesla定量的磁化率マップ(QSM)によるOEF画像を用いた頸動脈内膜剥離術後過灌流出現の予知
    野村 順一, 上野 育子, 佐々木 真理, 工藤 與亮, 山下 典生, 伊藤 賢司, 松本 昌泰, 及川 公樹, 藤原 俊朗, 千田 光平, 寺崎 一典, 小林 正和, 吉田 研二, 小笠原 邦昭
    脳循環代謝 日本脳循環代謝学会 29 (1) 169 - 169 0915-9401 2017/11 [Not refereed][Not invited]
  • Hiroyuki Sugimori, Noriyuki Fujima, Yuriko Suzuki, Hiroyuki Hamaguchi, Kinya Ishizaka, Kohsuke Kudo
    Magnetic resonance imaging 43 136 - 143 0730-725X 2017/11 [Refereed][Not invited]
     
    PURPOSE: To establish an optimized sequence design for fast acceleration of arterial spin labeling (ASL)-based time-resolved magnetic resonance angiography (MRA) by acquisition of control and labeled images in the same shot (fast ACTRESS) and a scan time of <1min, for the evaluation of intracranial vessels. MATERIALS AND METHODS: Ten healthy volunteers with no unilateral symptomatic arterial stenosis, who underwent 3-tesla MRI, were investigated. Imaging parameters for the fast ACTRESS sequence were set with an acquisition time of 45s. During post-processing, the first phase in the multi-phase readout, which was defined as the control image, was subtracted from each of the other phases. Thus, four-dimensional (4D)-MRA images of each phase were obtained. The maximum intensity projection was used for the reconstruction of 4D-MRA images and time-to-signal intensity curves (TIC) obtained for each vessel. The area under the curve (AUC), peak time, and maximum signal intensity were obtained from TIC. The different labeling types were broadly divided into six groups: L1, L2, L3, L4, L5, and L6 according to the actual number of labeling pulse. RESULTS: A total of 5040 regions of interest were evaluated. The peak SI of L3, except for those in the A2 segment of the anterior cerebral artery, was significantly higher than that of L5. However, there were no significant differences between L4 and L5. Although the AUCs of L3 and L4 for anterior circulation were relatively higher than that of the other subgroups, the AUC of L3 was significantly higher than that of L4. CONCLUSION: The fast ACTRESS was optimized and indicated that the labeling type of L3 was the most appropriate for the well visualization of intracranial arteries. The fast ACTRESS sequence was useful to acquire well-delineated images of intracranial vessels in ˂1min.
  • Tadao Aikawa, Noriko Oyama-Manabe, Masanao Naya, Hiroshi Ohira, Ayako Sugimoto, Ichizo Tsujino, Masahiko Obara, Osamu Manabe, Kohsuke Kudo, Hiroyuki Tsutsui, Nagara Tamaki
    European radiology 27 (10) 4054 - 4063 0938-7994 2017/10 [Refereed][Not invited]
     
    OBJECTIVES: To evaluate the diagnostic value of delayed contrast-enhanced computed tomography (DE-CT) for cardiac sarcoidosis (CS) in patients with or without implantable devices, including a quantitative comparison with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). METHODS: Twenty-four patients (mean age, 64 ± 9 years; 17 women) with known or suspected CS underwent retrospective electrocardiogram-gated DE-CT at 80 kV with knowledge-based iterative model reconstruction. Fourteen patients without implantable devices also underwent LGE-CMR, while ten with pacemakers or implantable cardioverter-defibrillators did not. The presence of hyperenhanced myocardium was assessed visually and quantitatively using a 5-standard deviation threshold above the mean of remote myocardium. RESULTS: Inter-observer agreement for visual detection of hyperenhanced segments on DE-CT was excellent in patients with implantable devices and in those without (κ = 0.91 and κ = 0.94, respectively). Comparisons of the percent area of hyperenhanced myocardium between DE-CT and LGE-CMR on both per-patient and per-segment analyses showed good correlations (r = 0.96 and r = 0.83, respectively; p < 0.001). The sensitivity and specificity of DE-CT for the diagnosis of CS were 94% and 33%. CONCLUSIONS: The extent of hyperenhanced lesion with DE-CT showed good agreement with LGE-CMR results. DE-CT showed high sensitivity for detecting CS and may be useful particularly in patients with contraindications to CMR. KEY POINTS: • Delayed contrast-enhanced CT (DE-CT) can be applied to patients with implantable devices. • DE-CT can detect cardiac sarcoidosis (CS) lesions similarly to cardiac MRI. • DE-CT shows high sensitivity for detecting CS. • DE-CT may be useful particularly in patients with contraindications to cardiac MRI.
  • Ikuko Uwano, Kohsuke Kudo, Ryota Sato, Kuniaki Ogasawara, Hiroyuki Kameda, Jun-Ichi Nomura, Futoshi Mori, Fumio Yamashita, Kenji Ito, Kunihiro Yoshioka, Makoto Sasaki
    Stroke 48 (8) 2136 - 2141 0039-2499 2017/08 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: The oxygen extraction fraction (OEF) is an effective metric to evaluate metabolic reserve in chronic ischemia. However, OEF is considered to be accurately measured only when using positron emission tomography (PET). Thus, we investigated whether OEF maps generated by magnetic resonance quantitative susceptibility mapping (QSM) at 7 Tesla enabled detection of OEF changes when compared with those obtained with PET. METHODS: Forty-one patients with chronic stenosis/occlusion of the unilateral internal carotid artery or middle cerebral artery were examined using 7 Tesla-MRI and PET scanners. QSM images were obtained from 3-dimensional T2*-weighted images, using a multiple dipole-inversion algorithm. OEF maps were generated based on susceptibility differences between venous structures and brain tissues on QSM images. OEF ratios of the ipsilateral middle cerebral artery territory against the contralateral side were calculated on the QSM-OEF and PET-OEF images, using an anatomic template. RESULTS: The OEF ratio in the middle cerebral artery territory showed significant correlations between QSM-OEF and PET-OEF maps (r=0.69; P<0.001), especially in patients with a substantial increase in the PET-OEF ratio of 1.09 (r=0.79; P=0.004), although showing significant systematic biases for the agreements. An increased QSM-OEF ratio of >1.09, as determined by receiver operating characteristic analysis, showed a sensitivity and specificity of 0.82 and 0.86, respectively, for the substantial increase in the PET-OEF ratio. Absolute QSM-OEF values were significantly correlated with PET-OEF values in the patients with increased PET-OEF. CONCLUSIONS: OEF ratios on QSM-OEF images at 7 Tesla showed a good correlation with those on PET-OEF images in patients with unilateral steno-occlusive internal carotid artery/middle cerebral artery lesions, suggesting that noninvasive OEF measurement by MRI can be a substitute for PET.
  • Takeshi Soyama, Daisuke Yoshida, Yusuke Sakuhara, Ryo Morita, Daisuke Abo, Kohsuke Kudo
    Cardiovascular and interventional radiology 40 (6) 947 - 952 0174-1551 2017/06 [Refereed][Not invited]
     
    The steerable microcatheter (SwiftNINJA, Sumitomo Bakelite, Tokyo, Japan), which has a remote-controlled flexible tip manipulated using a dial in the handgrip, was recently developed and delivered to the market. This device enables the user to change the angle of the microcatheter tip manually, and potentially makes selective catheterisation easier. We evaluated its unique characteristics and utility in selective catheterisation and coil embolization. This article describes: (1) the advantages of this device in catheterisations involving acute angle branches, and (2) a new technique of compact coil packing with the use of intentional folding by the bendable tip of the catheter.
  • Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Taisuke Harada, Yukie Shimizu, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato
    Oncotarget 8 (20) 33631 - 33643 1949-2553 2017/05/16 [Refereed][Not invited]
     
    We assessed parameters of advanced diffusion weighted imaging (DWI) models for the prediction of the tumor growth rate in 55 head and neck squamous cell carcinoma (HNSCC) patients. The DWI acquisition used single-shot spin-echo echo-planar imaging with 12 b-values (0-2000). We calculated 14 DWI parameters using mono-exponential, bi-exponential, tri-exponential, stretched exponential and diffusion kurtosis imaging models. We directly measured the tumor growth rate from two sets of different-date imaging data. We divided the patients into a discovery group (n = 40) and validation group (n = 15) based on their MR acquisition dates. In the discovery group, we performed univariate and multivariate regression analyses to establish the multiple regression equation for the prediction of the tumor growth rate using diffusion parameters. The equation obtained with the discovery group was applied to the validation group for the confirmation of the equation's accuracy. After the univariate and multivariate regression analyses in the discovery-group patients, the estimated tumor growth rate equation was established by using the significant parameters of intermediate diffusion coefficient D2 and slow diffusion coefficient D3 obtained by the tri-exponential model. The discovery group's correlation coefficient between the estimated and directly measured tumor growth rates was 0.74. In the validation group, the correlation coefficient (r = 0.66) and intra-class correlation coefficient (0.65) between the estimated and directly measured tumor growth rates were respectively good. In conclusion, advanced DWI model parameters can be a predictor for determining HNSCC patients' tumor growth rate.
  • Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Kohsuke Kudo, Hiroki Shirato
    European journal of radiology 90 14 - 19 0720-048X 2017/05 [Refereed][Not invited]
     
    PURPOSE: To evaluate the detectability of the residual tumour in post-treatment granulation tissue using parameters obtained with an advanced diffusion model in patients with head and neck squamous cell carcinoma (HNSCC) treated by chemoradiation therapy. MATERIALS AND METHODS: We retrospectively evaluated 23 patients with HNSCC after the full course of chemoradiation therapy. The diffusion-weighted image (DWI) acquisition used single-shot spin-echo echo-planar imaging with 11 b-values (0-1000). We calculated 10 DWI parameters using a mono-exponential model, a bi-exponential model, a stretched exponential model (SEM), a diffusion kurtosis imaging (DKI) model and a statistical diffusion model (SDM) in the region of interest (ROI) placed on the post-treatment granulation tissue. The presence of residual tumour was determined by histological findings or clinical follow-up. RESULTS: Among the 23 patients, seven patients were revealed to have residual tumour. The univariate analysis revealed significant differences in six parameters between the patients with and without residual tumour. From the receiver operating characteristic curve analysis, the highest area under curve was detected in the center of the Gaussian distribution of diffusion coefficient (Ds) obtained by the SDM. The multivariate analysis revealed that the Ds and diffusion heterogeneity (α) obtained by the SEM were predictors for the presence of residual tumour. CONCLUSION: DWI parameters obtained by advanced fitting models will be one of the diagnostic tools for the detection of residual tumour.
  • Kohsuke Kudo, Ikuko Uwano, Toshinori Hirai, Ryuji Murakami, Hideo Nakamura, Noriyuki Fujima, Fumio Yamashita, Jonathan Goodwin, Satomi Higuchi, Makoto Sasaki
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 16 (2) 129 - 136 1347-3182 2017/04/10 [Refereed][Not invited]
     
    PURPOSE: The purpose of the present study was to compare different software algorithms for processing DSC perfusion images of cerebral tumors with respect to i) the relative CBV (rCBV) calculated, ii) the cutoff value for discriminating low- and high-grade gliomas, and iii) the diagnostic performance for differentiating these tumors. METHODS: Following approval of institutional review board, informed consent was obtained from all patients. Thirty-five patients with primary glioma (grade II, 9; grade III, 8; and grade IV, 18 patients) were included. DSC perfusion imaging was performed with 3-Tesla MRI scanner. CBV maps were generated by using 11 different algorithms of four commercially available software and one academic program. rCBV of each tumor compared to normal white matter was calculated by ROI measurements. Differences in rCBV value were compared between algorithms for each tumor grade. Receiver operator characteristics analysis was conducted for the evaluation of diagnostic performance of different algorithms for differentiating between different grades. RESULTS: Several algorithms showed significant differences in rCBV, especially for grade IV tumors. When differentiating between low- (II) and high-grade (III/IV) tumors, the area under the ROC curve (Az) was similar (range 0.85-0.87), and there were no significant differences in Az between any pair of algorithms. In contrast, the optimal cutoff values varied between algorithms (range 4.18-6.53). CONCLUSIONS: rCBV values of tumor and cutoff values for discriminating low- and high-grade gliomas differed between software packages, suggesting that optimal software-specific cutoff values should be used for diagnosis of high-grade gliomas.
  • Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Akiko Tsukahara, Yukie Shimizu, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato
    European radiology 27 (3) 956 - 965 0938-7994 2017/03 [Refereed][Not invited]
     
    OBJECTIVES: To evaluate the diagnostic value of intravoxel incoherent motion (IVIM) and diffusional kurtosis imaging (DKI) parameters in nasal or sinonasal squamous cell carcinoma (SCC) patients to determine local control/failure. METHODS: Twenty-eight patients were evaluated. MR acquisition used single-shot spin-echo EPI with 12 b-values. Quantitative parameters (mean value, 25th, 50th and 75th percentiles) of IVIM (perfusion fraction f, pseudo-diffusion coefficient D*, and true-diffusion coefficient D), DKI (kurtosis value K, kurtosis corrected diffusion coefficient Dk) and apparent diffusion coefficient (ADC) were calculated. Parameter values at both the pretreatment and early-treatment period, and the percentage change between these two periods were obtained. RESULTS: Multivariate logistic regression analysis: the percentage changes of D (mean, 25th, 50th, 75th), K (mean, 50th, 75th), Dk (mean, 25th, 50th), and ADC (mean, 25th, 50th) were predictors of local control. ROC curve analysis: the parameter with the highest accuracy = the percentage change of D value with the histogram 25th percentile (0.93 diagnostic accuracy). Multivariate Cox regression analyses: the percentage changes of D (mean, 25th, 50th), K (mean, 50th, 75th), Dk (mean, 25th, 50th) and ADC (mean, 25th, 50th) are predictors. CONCLUSIONS: IVIM and DKI parameters, especially the D-value's histogram 25th percentile, are useful for predicting local control. KEY POINTS: • Noninvasive assessment of treatment outcome in SCC patients was achieved using IVIM/DKI. • Several IVIM and DKI parameters can predict the local control. • Especially, the D-value's histogram 25th percentile has high diagnostic accuracy.
  • Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Yukie Shimizu, Atsushi Yoshida, Taisuke Harada, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato
    Magnetic resonance imaging 36 16 - 23 0730-725X 2017/02 [Refereed][Not invited]
     
    PURPOSE: We assessed advanced fitting models of diffusion weighted imaging (DWI) in head/neck squamous cell carcinoma (HNSCC) patients to determine the best goodness of fit and correlations among diffusion parameters. We compared these results with those of dynamic contrast-enhanced (DCE) perfusion parameters. MATERIALS AND METHODS: We retrospectively evaluated 32 HNSCC patients (12 sinonasal, 20 pharynx/oral cavity). The DWI acquisition used single-shot spin-echo echo-planar imaging (EPI) with 12 b-values (0-2000). We calculated 14 DWI parameters using mono-exponential, bi-exponential, and tri-exponential models, stretched exponential model (SEM) and diffusion kurtosis imaging (DKI) models. We compared each model's goodness of fit using the residual sum of squares (RSS), Akaike Information Criterion (AIC) and Bayesian information criterion (BIC) value. We determined the correlation between each pair of DWI parameters and between each DWI parameter and DCE perfusion parameter. RESULTS: The tri-exponential fit's RSS, AIC and BIC values were significantly smaller than those for bi-exponential fit. The RSS, AIC and BIC values of the SEM fit and DKI fit were significantly smaller than mono-exponential model. Significant correlations were observed in 30 pairs (sinonasal cavity) and 31 (sinonasal cavity group) among 91 DWI parameter combinations. Significant correlations were also observed in nine pairs (both sinonasal cavity and pharynx/oral cavity group) among 64 DWI/DCE perfusion parameter pairs, in particular, high positive correlations between the tri-exponential model's intermediate diffusion fraction (f2) and the volume of the extracellular extravascular space per unit volume of tissue (ve) were observed in both patient groups. CONCLUSION: We identified several correlations between DWI parameters by advanced fitting models and correlations between DWI and DCE parameters. These will help determine HNSCC patients' detailed tissue structures.
  • Taisuke Harada, Kohsuke Kudo, Ikuko Uwano, Fumio Yamashita, Hiroyuki Kameda, Tsuyoshi Matsuda, Makoto Sasaki, Hiroki Shirato
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 16 (1) 23 - 31 1347-3182 2017/01/10 [Refereed][Not invited]
     
    PURPOSE: The B0 and B1+ maps required for calculation of the radiofrequency (RF) pulse of parallel transmission (pTx) are obtained in calibration scans; however, they may be affected by respiratory motion. We aimed to compare the reproducibility of B0 and B1+ maps and gradient echo (GRE) images of the brain scanned with pTx at 7T between free-breathing (FB) and breath-holding (BH) conditions during the calibration scan. METHODS: Nine healthy volunteers were scanned by 7T MRI using a two-channel quadrature head coil. In the pTx calibration scans performed with FB and BH, the B0 map was obtained from two different TE images and the B1+ map was calculated by the Bloch-Siegert method. A GRE image (gradient-recalled-acquisition in steady state) was also obtained with RF shimming and RF design of pTx with spoke method, as well as quadrature transmission (qTx). All the scans were repeated over five sessions. The reproducibility of the B0 and B1+ maps and GRE image was evaluated with region-of-interest measurements using inter-session standard deviation (SD) and coefficient of variation (CV) values. Intensity homogeneity of GRE images was also assessed with in-plane CV. RESULTS: Inter-session SDs of B0 and B1+ maps were significantly smaller in BH (P < 0.01). Inter-session CVs of GRE images were significantly smaller in qTx than BH and FB (P < 0.01, both); however, the CVs of BH were significantly smaller (P < 0.01). In-plane CVs of FB and BH with RF shimming were not significantly different with qTx; however, CVs of FB and BH with RF design were significantly smaller than those of qTx (P < 0.05 and P < 0.01, respectively). CONCLUSION: BH could improve the reproducibility of B0 and B1+ maps in pTx calibration scans and GRE images. These results might facilitate the development of pTx in human brain at 7T.
  • Ikuko Uwano, Makoto Sasaki, Kohsuke Kudo, Timothé Boutelier, Hiroyuki Kameda, Futoshi Mori, Fumio Yamashita
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 16 (1) 32 - 37 1347-3182 2017/01/10 [Refereed][Not invited]
     
    PURPOSE: The Bayesian estimation algorithm improves the precision of bolus tracking perfusion imaging. However, this algorithm cannot directly calculate Tmax, the time scale widely used to identify ischemic penumbra, because Tmax is a non-physiological, artificial index that reflects the tracer arrival delay (TD) and other parameters. We calculated Tmax from the TD and mean transit time (MTT) obtained by the Bayesian algorithm and determined its accuracy in comparison with Tmax obtained by singular value decomposition (SVD) algorithms. METHODS: The TD and MTT maps were generated by the Bayesian algorithm applied to digital phantoms with time-concentration curves that reflected a range of values for various perfusion metrics using a global arterial input function. Tmax was calculated from the TD and MTT using constants obtained by a linear least-squares fit to Tmax obtained from the two SVD algorithms that showed the best benchmarks in a previous study. Correlations between the Tmax values obtained by the Bayesian and SVD methods were examined. RESULTS: The Bayesian algorithm yielded accurate TD and MTT values relative to the true values of the digital phantom. Tmax calculated from the TD and MTT values with the least-squares fit constants showed excellent correlation (Pearson's correlation coefficient = 0.99) and agreement (intraclass correlation coefficient = 0.99) with Tmax obtained from SVD algorithms. CONCLUSIONS: Quantitative analyses of Tmax values calculated from Bayesian-estimation algorithm-derived TD and MTT from a digital phantom correlated and agreed well with Tmax values determined using SVD algorithms.
  • Noriyuki Fujima, Toshiya Osanai, Yukie Shimizu, Atsushi Yoshida, Taisuke Harada, Naoki Nakayama, Kohsuke Kudo, Kiyohiro Houkin, Hiroki Shirato
    Journal of magnetic resonance imaging : JMRI 44 (4) 834 - 45 1053-1807 2016/10 [Refereed][Not invited]
     
    PURPOSE: To evaluate the utility of a vessel-selective four-dimensional (4D) magnetic resonance angiography (MRA) technique for the evaluation of intracranial arteriovenous malformations (AVMs). MATERIALS AND METHODS: Twelve AVM patients were evaluated retrospectively. Time-of-flight (TOF) MRA, nonvessel-selective 4D-MRA (NS-4D-MRA), and vessel-selective 4D-MRA (VS-4D-MRA) were performed using a 3T MR unit in all patients, and used to identify feeding arteries and draining veins and measure nidus size. The diagnostic accuracy of the three techniques was compared using digital subtraction angiography (DSA). If a multifeeder was observed, the percentage of blood flow of each feeding artery to the entire nidus was evaluated and compared to the DSA findings using the "error value," defined as the degree of overestimation of the blood flow. All imaging findings were assessed by two neuroradiologists. RESULTS: In both raters, the detectability of feeding arteries by VS-4D-MRA (12 and 11 patients) was significantly higher than those of TOF-MRA (7 and 6 patients) and NS-4D-MRA (8 and 7 patients) (P < 0.016). The detectability of drainer veins by TOF-MRA (10 and 10 patients) was significantly higher than that of VS-4D-MRA (7 and 6 patients). In the percentage of the blood flow of each feed artery to the entire nidus, the DSA findings (error value; 27.1 ± 5.7) indicated overestimations of the blood flow compared to the VS-4D-MRA (error value; 7.1 ± 3.9) (P < 0.001). CONCLUSION: VS-4D-MRA was shown to be a useful technique for the evaluation of intracranial AVMs, especially for detecting feed arteries and estimating details of the nidus structure. J. MAGN. RESON. IMAGING 2016;44:834-845.
  • Kohsuke Kudo, Tian Liu, Toshiyuki Murakami, Jonathan Goodwin, Ikuko Uwano, Fumio Yamashita, Satomi Higuchi, Yi Wang, Kuniaki Ogasawara, Akira Ogawa, Makoto Sasaki
    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 36 (8) 1424 - 33 0271-678X 2016/08 [Refereed][Not invited]
     
    The purposes of this study are to establish oxygen extraction fraction (OEF) measurements using quantitative susceptibility mapping (QSM) of magnetic resonance imaging (MRI), and to compare QSM-OEF data with the gold standard (15)O positron emission tomography (PET). Twenty-six patients with chronic unilateral internal carotid artery or middle cerebral artery stenosis or occlusion, and 15 normal subjects were included. MRI scans were conducted using a 3.0 Tesla scanner with a three-dimensional spoiled gradient recalled sequence. QSM images were created using the morphology-enabled dipole inversion method, and OEF maps were generated from QSM images using extraction of venous susceptibility induced by deoxygenated hemoglobin. Significant correlation of relative OEF ratio to contra-lateral hemisphere between QSM-OEF and PET-OEF was observed (r = 0.62, p < 0.001). The local (intra-section) correlation was also significant (r = 0.52, p < 0.001) in patients with increased PET-OEF. The sensitivity and specificity of OEF increase in QSM was 0.63 (5/8) and 0.89 (16/18), respectively, in comparison with PET. In conclusion, good correlation was achieved between QSM-OEF and PET-OEF in the identification of elevated OEF in affected hemispheres of patients with unilateral chronic steno-occlusive disease.
  • Takeshi Soyama, Yusuke Sakuhara, Kohsuke Kudo, Daisuke Abo, Jeff Wang, Yoichi M Ito, Yu Hasegawa, Hiroki Shirato
    Journal of medical ultrasonics (2001) 43 (3) 327 - 35 1346-4523 2016/07 [Refereed][Not invited]
     
    PURPOSE: This preliminary study compared ultrasonography-computed tomography (US-CT) fusion imaging and conventional ultrasonography (US) for accuracy and time required for target identification using a combination of real phantoms and sets of digitally modified computed tomography (CT) images (digital/real hybrid phantoms). METHODS: In this randomized prospective study, 27 spheres visible on B-mode US were placed at depths of 3.5, 8.5, and 13.5 cm (nine spheres each). All 27 spheres were digitally erased from the CT images, and a radiopaque sphere was digitally placed at each of the 27 locations to create 27 different sets of CT images. Twenty clinicians were instructed to identify the sphere target using US alone and fusion imaging. The accuracy of target identification of the two methods was compared using McNemar's test. The mean time required for target identification and error distances were compared using paired t tests. RESULTS: At all three depths, target identification was more accurate and the mean time required for target identification was significantly less with US-CT fusion imaging than with US alone, and the mean error distances were also shorter with US-CT fusion imaging. CONCLUSION: US-CT fusion imaging was superior to US alone in terms of accurate and rapid identification of target lesions.
  • Edwin Bennink, Jaap Oosterbroek, Kohsuke Kudo, Max A Viergever, Birgitta K Velthuis, Hugo W A M de Jong
    Journal of medical imaging (Bellingham, Wash.) 3 (2) 026003 - 026003 2329-4302 2016/04 [Refereed][Not invited]
     
    Although computed tomography (CT) perfusion (CTP) imaging enables rapid diagnosis and prognosis of ischemic stroke, current CTP analysis methods have several shortcomings. We propose a fast nonlinear regression method with a box-shaped model (boxNLR) that has important advantages over the current state-of-the-art method, block-circulant singular value decomposition (bSVD). These advantages include improved robustness to attenuation curve truncation, extensibility, and unified estimation of perfusion parameters. The method is compared with bSVD and with a commercial SVD-based method. The three methods were quantitatively evaluated by means of a digital perfusion phantom, described by Kudo et al. and qualitatively with the aid of 50 clinical CTP scans. All three methods yielded high Pearson correlation coefficients ([Formula: see text]) with the ground truth in the phantom. The boxNLR perfusion maps of the clinical scans showed higher correlation with bSVD than the perfusion maps from the commercial method. Furthermore, it was shown that boxNLR estimates are robust to noise, truncation, and tracer delay. The proposed method provides a fast and reliable way of estimating perfusion parameters from CTP scans. This suggests it could be a viable alternative to current commercial and academic methods.
  • Rie Mimura, Fumi Kato, Khin Khin Tha, Kohsuke Kudo, Yosuke Konno, Noriko Oyama-Manabe, Tatsuya Kato, Hidemichi Watari, Noriaki Sakuragi, Hiroki Shirato
    Japanese journal of radiology 34 (3) 229 - 37 1867-1071 2016/03 [Refereed][Not invited]
     
    PURPOSE: This study aimed to evaluate whether histogram analysis of the apparent diffusion coefficient (ADC) of a solid tumor component could distinguish borderline ovarian tumors from ovarian carcinoma. MATERIALS AND METHODS: Sixteen pathologically proven borderline tumors and 21 carcinomas were retrospectively examined. Magnetic resonance (1.5-T) image data sets were coregistered, and the solid components of each tumor were semiautomatically segmented. ADC histograms of the solid components were extracted; modes, minimums, means, and 10th, 25th, 50th, 75th, and 90th percentiles of the histograms were compared between the two tumor types, and receiver-operating characteristic (ROC) analysis was performed. RESULTS: The mode, minimum, mean, 10th, 25th, 50th, and 75th percentile ADC values of solid components of borderline tumors were significantly larger than those of carcinomas. Among these, the 10th percentile values had the lowest p value (p = 0.0003). At ROC analysis, the area under the curve (AUC) in the 10th percentile was the greatest (0.854), and the best cutoff value in the 10th percentile provided the highest specificity (93.8 %). CONCLUSIONS: ADC histograms of solid tumor components facilitated the distinction between borderline ovarian tumors and carcinoma. The 10th percentile ADC values had the best diagnostic performance.
  • N Fujima, D Yoshida, T Sakashita, A Homma, A Tsukahara, K K Tha, K Kudo, H Shirato
    AJNR. American journal of neuroradiology 37 (2) 342 - 8 2016/02 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: For the assessment of the treatment response in non-surgical treatment, tumor blood flow provides the functional information of the tumor which is different from the morphological information such as tumor volume. The purpose of this study was to evaluate the diagnostic value of tumor blood flow values obtained by pseudocontinuous arterial spin-labeling in patients with head and neck squamous cell carcinoma. MATERIALS AND METHODS: Forty-one patients with head and neck squamous cell carcinoma were evaluated by using pseudocontinuous arterial spin-labeling. Quantitative tumor blood flow was calculated at the pretreatment and the early treatment periods in all the patients, and the percentage change of tumor blood flow between the two was calculated. At the early treatment period, based on their tumor volume reduction rate, we divided the patients into stable disease and partial response groups for a subgroup analysis. The local control or failure was confirmed either by histopathology or by radiologic evaluation within the follow-up. RESULTS: Pretreatment tumor blood flow in patients in the failure group was significantly lower than that in patients in the local control group. In the subgroup analysis of patients with stable disease, the percentage change of tumor blood flow was significantly larger (due to the tumor blood flow increase from pretreatment value) in the local control group than in the failure group. In addition, in patients with a partial response, the percentage change of tumor blood flow was significantly smaller (due to the tumor blood flow decrease from the pretreatment value) in the local control group than in the failure group. The accuracy for determination of the local control group or the failure group in pretreatment tumor blood flow was 0.83 and that in the combination use of the percentage change of tumor blood flow and tumor volume in the early treatment period was 0.93. CONCLUSIONS: Tumor blood flow obtained by pseudocontinuous arterial spin-labeling can be useful for the determination of local control. The combined use of the percentage change of tumor blood flow and tumor volume had particularly high diagnostic accuracy.
  • Yi Cui, Khin Khin Tha, Shunsuke Terasaka, Shigeru Yamaguchi, Jeff Wang, Kohsuke Kudo, Lei Xing, Hiroki Shirato, Ruijiang Li
    Radiology 278 (2) 546 - 53 0033-8419 2016/02 [Refereed][Not invited]
     
    PURPOSE: To develop and independently validate prognostic imaging biomarkers for predicting survival in patients with glioblastoma on the basis of multiregion quantitative image analysis. MATERIALS AND METHODS: This retrospective study was approved by the local institutional review board, and informed consent was waived. A total of 79 patients from two independent cohorts were included. The discovery and validation cohorts consisted of 46 and 33 patients with glioblastoma from the Cancer Imaging Archive (TCIA) and the local institution, respectively. Preoperative T1-weighted contrast material-enhanced and T2-weighted fluid-attenuation inversion recovery magnetic resonance (MR) images were analyzed. For each patient, we semiautomatically delineated the tumor and performed automated intratumor segmentation, dividing the tumor into spatially distinct subregions that demonstrate coherent intensity patterns across multiparametric MR imaging. Within each subregion and for the entire tumor, we extracted quantitative imaging features, including those that fully capture the differential contrast of multimodality MR imaging. A multivariate sparse Cox regression model was trained by using TCIA data and tested on the validation cohort. RESULTS: The optimal prognostic model identified five imaging biomarkers that quantified tumor surface area and intensity distributions of the tumor and its subregions. In the validation cohort, our prognostic model achieved a concordance index of 0.67 and significant stratification of overall survival by using the log-rank test (P = .018), which outperformed conventional prognostic factors, such as age (concordance index, 0.57; P = .389) and tumor volume (concordance index, 0.59; P = .409). CONCLUSION: The multiregion analysis presented here establishes a general strategy to effectively characterize intratumor heterogeneity manifested at multimodality imaging and has the potential to reveal useful prognostic imaging biomarkers in glioblastoma.
  • Chengbo Tan, Hideo Shichinohe, Zifeng Wang, Shuji Hamauchi, Takeo Abumiya, Naoki Nakayama, Ken Kazumata, Tsuneo Ito, Kohsuke Kudo, Shigeru Takamoto, Kiyohiro Houkin
    Stem Cells International 2016 1687-9678 2016 [Refereed][Not invited]
     
    Currently, there is increasing interest in human bone marrow stromal cells (hBMSCs) as regeneration therapy against cerebral stroke. The aim of the present study was to evaluate the feasibility and validity of hBMSC cultures with allogeneic platelet lysates (PLs). Platelet concentrates (PC) were harvested from healthy volunteers and made into single donor-derived PL (sPL). The PL mixtures (mPL) were made from three different sPL. Some growth factors and platelet cell surface antigens were detected by enzyme-linked immunosorbent assay (ELISA). The hBMSCs cultured with 10% PL were analyzed for their proliferative potential, surface markers, and karyotypes. The cells were incubated with superparamagnetic iron oxide (SPIO) agents and injected into a pig brain. MRI and histological analysis were performed. Consequently, nine lots of sPL and three mPL were prepared. ELISA analysis showed that PL contained adequate growth factors and a particle of platelet surface antigens. Cell proliferation capacity of PLs was equivalent to or higher than that of fetal calf serum (FCS). No contradiction in cell surface markers and no chromosomal aberrations were found. The MRI detected the distribution of SPIO-labeled hBMSCs in the pig brain. In summary, the hBMSCs cultured with allogeneic PL are suitable for cell therapy against stroke.
  • Suguru Yokosawa, Makoto Sasaki, Yoshitaka Bito, Kenji Ito, Fumio Yamashita, Jonathan Goodwin, Satomi Higuchi, Kohsuke Kudo
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 15 (1) 41 - 8 1347-3182 2016 [Refereed][Not invited]
     
    PURPOSE: To shorten acquisition of diffusion kurtosis imaging (DKI) in 1.5-tesla magnetic resonance (MR) imaging, we investigated the effects of the number of b-values, diffusion direction, and number of signal averages (NSA) on the accuracy of DKI metrics. METHODS: We obtained 2 image datasets with 30 gradient directions, 6 b-values up to 2500 s/mm(2), and 2 signal averages from 5 healthy volunteers and generated DKI metrics, i.e., mean, axial, and radial kurtosis (MK, K∥, and K⊥) maps, from various combinations of the datasets. These maps were estimated by using the intraclass correlation coefficient (ICC) with those from the full datasets. RESULTS: The MK and K⊥ maps generated from the datasets including only the b-value of 2500 s/mm(2) showed excellent agreement (ICC, 0.96 to 0.99). Under the same acquisition time and diffusion directions, agreement was better of MK, K∥, and K⊥ maps obtained with 3 b-values (0, 1000, and 2500 s/mm(2)) and 4 signal averages than maps obtained with any other combination of numbers of b-value and varied NSA. Good agreement (ICC > 0.6) required at least 20 diffusion directions in all the metrics. CONCLUSION: MK and K⊥ maps with ICC greater than 0.95 can be obtained at 1.5T within 10 min (b-value = 0, 1000, and 2500 s/mm(2); 20 diffusion directions; 4 signal averages; slice thickness, 6 mm with no interslice gap; number of slices, 12).
  • Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Kenji Hirata, Tohru Shiga, Kohsuke Kudo, Hiroki Shirato
    PloS one 11 (11) e0166236  1932-6203 2016 [Refereed][Not invited]
     
    OBJECTIVE: To determine the relationship between tumor glucose metabolism and tumor blood flow (TBF) in head and neck squamous cell carcinoma (HNSCC). METHODS: We retrospectively analyzed 57 HNSCC patients. Tumor glucose metabolism was assessed by maximum and mean standardized uptake values (SUVmax and SUVmean) obtained by 18F-fluorodeoxyglucose positron-emission tomography. TBF values were obtained by arterial spin labeling with 3-tesla MRI. The correlations between both SUVs and TBF were assessed in the total series and among patients divided by T-stage (T1-T3 and T4 groups) and tumor location (pharynx/oral cavity and sinonasal cavity groups). Pearson's correlation coefficients were calculated for significant correlations. RESULTS: Significant correlations were detected: a negative correlation in the advanced T-stage group (TBF and SUV max: r, -0.61, SUVmean: r, -0.62), a positive correlation in the non-advanced T-stage pharynx/oral cavity group (TBF and SUVmax: r, 0.70, SUVmean: r, 0.73), a negative correlation in the advanced T-stage pharynx/oral cavity group (TBF and SUVmax: r, -0.62, SUVmean: r, -0.65), and a negative correlation in the advanced T-stage sinonasal cavity group (TBF and SUVmax: r, -0.61, SUVmean: r, -0.65). CONCLUSION: Significant correlations between glucose uptake and TBF in HNSCC were revealed by the division of T-stage and tumor location.
  • Chengbo Tan, Hideo Shichinohe, Zifeng Wang, Shuji Hamauchi, Takeo Abumiya, Naoki Nakayama, Ken Kazumata, Tsuneo Ito, Kohsuke Kudo, Shigeru Takamoto, Kiyohiro Houkin
    Stem cells international 2016 6104780 - 6104780 1687-966X 2016 [Refereed][Not invited]
     
    Currently, there is increasing interest in human bone marrow stromal cells (hBMSCs) as regeneration therapy against cerebral stroke. The aim of the present study was to evaluate the feasibility and validity of hBMSC cultures with allogeneic platelet lysates (PLs). Platelet concentrates (PC) were harvested from healthy volunteers and made into single donor-derived PL (sPL). The PL mixtures (mPL) were made from three different sPL. Some growth factors and platelet cell surface antigens were detected by enzyme-linked immunosorbent assay (ELISA). The hBMSCs cultured with 10% PL were analyzed for their proliferative potential, surface markers, and karyotypes. The cells were incubated with superparamagnetic iron oxide (SPIO) agents and injected into a pig brain. MRI and histological analysis were performed. Consequently, nine lots of sPL and three mPL were prepared. ELISA analysis showed that PL contained adequate growth factors and a particle of platelet surface antigens. Cell proliferation capacity of PLs was equivalent to or higher than that of fetal calf serum (FCS). No contradiction in cell surface markers and no chromosomal aberrations were found. The MRI detected the distribution of SPIO-labeled hBMSCs in the pig brain. In summary, the hBMSCs cultured with allogeneic PL are suitable for cell therapy against stroke.
  • Takashi Ohno, Kohsuke Kudo, Greg Zaharchuk, Noriyuki Fujima, Hiroki Shirato
    Japanese journal of radiology 34 (1) 28 - 34 1867-1071 2016/01 [Refereed][Not invited]
     
    PURPOSE: The purpose of the present study was to determine optimal threshold of vascular pixel elimination (VPE) for CT perfusion (CTP) and to assess diagnostic accuracy of CTP by comparing with xenon enhanced CT (XeCT) in moyamoya disease. MATERIALS AND METHODS: Twenty-three patients underwent XeCT and CTP. Cerebral blood flow (CBF) images were generated for XeCT and CTP using nine types of software. Region of interest (ROI) measurement was performed on XeCT-CBF and CTP-CBF. Linear regression analysis was performed between XeCT-CBF and CTP-CBF in all software, without and with VPE. The Pearson correlation coefficient was calculated, and an optimal threshold was determined based on maximum correlation coefficients. Correlation coefficients at various VPE thresholds including data of no-VPE were compared with each other. The maximum correlation coefficient at the optimal threshold was also compared. RESULTS: Optimal thresholds varied among software types (0.8-2.2 and 7-14 ml/100 g in relative and absolute VPE, respectively). There were significant differences between correlation coefficients at a range of VPE thresholds compared to no-VPE in most software types. There were significant differences in maximum correlation coefficient at optimal threshold among various software types. CONCLUSION: Optimal threshold of VPE for CTP could be determined and diagnostic accuracy of CTP varied among software types in moyamoya disease.
  • Fumi Kato, Kohsuke Kudo, Hiroko Yamashita, Jeff Wang, Mitsuchika Hosoda, Kanako C Hatanaka, Rie Mimura, Noriko Oyama-Manabe, Hiroki Shirato
    European journal of radiology 85 (1) 96 - 102 0720-048X 2016/01 [Refereed][Not invited]
     
    PURPOSE: To compare the morphology and minimum apparent diffusion coefficient (ADC) values among breast cancer subtypes. METHODS: Ninety-three patients, who underwent breast MRI and collectively had 98 pathologically proven invasive carcinomas, were enrolled. Morphology was evaluated according to BIRADS-MRI. Minimum ADC was measured. Morphology and minimum ADC were compared among subtypes. Multivariate logistic regression analyses were used to identify the characteristics associated with different subtypes. RESULTS: Oval/round shape was significantly associated with triple-negative (TN) cancer (TN vs. non-TN: 90.9% vs. 45.2%; p=0.0123). Rim enhancement was significantly less frequent in Luminal A (Luminal A vs. non-Luminal A: 34.2% vs. 76.1%; p=0.0003). The minimum ADC of Luminal A was significantly higher than that of Luminal B (HER2-negative) (834 vs. 748×10(-6)mm(2)/s; p<0.025). The minimum ADC of the TN-special type was significantly higher than that of TN-ductal (997 vs. 702×10(-6)mm(2)/s; p<0.025). On the multivariate analysis comparing the characteristics associated with Luminal A vs. Luminal B (HER2-negative), the internal enhancement characteristics of the mass and minimum ADC were significant factors. CONCLUSION: Morphology and minimum ADC would be useful in distinguishing breast cancer subtypes.
  • Hiroyuki Sugimori, Noriyuki Fujima, Yuriko Suzuki, Hiroyuki Hamaguchi, Motomichi Sakata, Kohsuke Kudo
    Magnetic resonance imaging 33 (10) 1338 - 1344 0730-725X 2015/12 [Refereed][Not invited]
     
    PURPOSE: Arterial spin labeling (ASL) methods have been widely used for evaluation of cerebral blood flow (CBF) by magnetic resonance imaging. However, ASL methods require setting of the post labeling delay (PLD) time for obtaining images. As the hemodynamic status cannot be estimated in each patient, the resultant quantitative values of blood flow may not be accurate. The multi-phase pseudo continuous arterial spin labeling (pCASL) method can be used to obtain images at various time-points. The purpose of this study was to create the transit-time maps for correcting the delayed blood flow and evaluate CBF using the transit-time maps obtained by the multi-phase pCASL method. MATERIALS AND METHODS: Twelve patients who underwent both 3.0-tesla magnetic resonance imaging (MRI) and single photon emission computed tomography with iodine-123-N-isopropyl-p-iodoamphetamine (123I-IMP) were investigated. This study was approved by the institutional review board of our institution. MRI acquisitions included PLD time-fixed (1525ms) and multi-phase pCASL sequences. The transit-time maps were calculated from multi-phase pCASL images by software. The transit-time maps were applied to PLD-fixed pCASL images pixel by pixel, for calculating the CBF value corrected for peak blood transit time. Regions of interest were drawn on the brain. IMP-CBF, ASL-CBF (default and corrected) and transit time were measured for each segment. RESULTS: Twelve patients and 264 segments were investigated. The mean IMP-CBF, ASL-CBF (default, corrected) and transit time were 28.4, 23.0, 29.6, [ml/min/100g] and 1977.5 [ms], respectively. There were no significant differences between IMP-CBF and ASL-CBF (corrected). CONCLUSION: CBF values can be corrected by using the transit-time maps obtained using the multi-phase pCASL method.
  • Noriyuki Fujima, Hiroyuki Kameda, Akiko Tsukahara, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato
    European journal of radiology 84 (11) 2187 - 93 0720-048X 2015/11 [Refereed][Not invited]
     
    OBJECTIVES: To investigate the diagnostic value of tumor blood flow (TBF) obtained with pseudo-continuous arterial spin labeling (pCASL) for the differentiation of squamous cell carcinoma (SCC) and malignant lymphoma (ML) in the nasal or sinonasal cavity. METHODS: Thirty-three patients with SCC and 6 patients with ML in the nasal or sinonasal cavity were retrospectively analyzed. Quantitative TBF values were obtained using whole-tumor region of interest (ROI) from pCASL data. The histogram analysis of TBF values within the tumor ROI was also performed by calculating the coefficient of variation (CV), kurtosis, and skewness. The mean TBF value, histogram CV, kurtosis and skewness of the patients with SCC were compared with those of the ML patients. The diagnostic accuracy to differentiate SCC from ML was also calculated by receiver operating characteristic (ROC) curve analysis. In addition, multiple logistic regression models were also performed to determine their independent predictive value, and diagnostic accuracy with the combined use of these parameters. RESULTS: Between the SCC and ML groups, significant differences were observed in mean TBF, CV, and kurtosis, but not in skewness. In ROC curve analysis, the diagnostic accuracy values for the differentiation of SCC from ML in mean TBF, CV, and kurtosis were all 0.87, respectively. Multiple logistic regression models revealed TBF and CV were respectively independent predictive value. With the combination of these parameters, the diagnostic accuracy was elevated to 0.97. CONCLUSIONS: The TBF value and its histogram analysis obtained with pCASL can help differentiate SCC and ML.
  • Yusuke Sakuhara, Saori Nishio, Ken Morita, Daisuke Abo, Yu Hasegawa, Noriaki Yuasa, Toshio Mochizuki, Takeshi Soyama, Koji Oba, Hiroki Shirato, Kohsuke Kudo
    Radiology 277 (1) 277 - 85 0033-8419 2015/10 [Refereed][Not invited]
     
    PURPOSE: To evaluate the safety and effectiveness of transcatheter arterial embolization (TAE) with ethanol in symptomatic patients with enlarged polycystic kidney disease. MATERIALS AND METHODS: This prospective study was institutional review board approved and was planned for patients with symptoms related to enlarged polycystic kidney disease, such as a markedly distended abdomen, gastroesophageal reflux, and abdominal pain. At the time of TAE, all patients were undergoing dialysis therapy for chronic renal failure, and their urinary volume had decreased to less than 500 mL per day. Bilateral renal TAE with absolute ethanol was performed, and changes in kidney volume, clinical symptoms, laboratory data, and complications were evaluated after TAE. The differences in patients' kidney volumes, clinical symptoms, abdominal circumference, and dry weights before and after TAE were analyzed with a mixed effect model. RESULTS: Fifteen patients (seven men and eight women; mean age, 57.7 years ± 5.3 [standard deviation]) were treated. Among the 15 patients, the follow-up period was 24 months in 13 patients, 6 months in one patient, and 3 months in one patient. The mean kidney volume was 3380 mL before renal TAE, and at 3, 12, and 24 months after TAE, it significantly decreased to 60.9%, 39.8%, and 32.1% of the pretherapeutic value, respectively (P < .001). All patients reported improved clinical symptoms within 3 months after TAE (P < .001). Abdominal circumferences were significantly decreased after TAE (P < .001). The dry weights also continued to significantly decreased until 6 months after TAE (P < .001), at which point they began to slightly increase until 24 months after TAE. Abdominal pain, nausea, and inflammatory response developed in all patients after TAE, but these symptoms improved with conservative treatment. Abscess formation was found in one kidney, and drainage catheter placement was performed. No major complications related to TAE occurred in the remaining patients. CONCLUSION: Renal contraction therapy by TAE with ethanol injection appears to be a safe and effective treatment in patients with symptomatic enlarged polycystic kidney disease.
  • Taisuke Harada, Takashige Abe, Fumi Kato, Ryuji Matsumoto, Hiromi Fujita, Sachiyo Murai, Naoto Miyajima, Kunihiko Tsuchiya, Satoru Maruyama, Kohsuke Kudo, Nobuo Shinohara
    BMC urology 15 91 - 91 1471-2490 2015/09/04 [Refereed][Not invited]
     
    BACKGROUND: To clarify the relationship between the probability of prostate cancer scaled using a 5-point Likert system and the biological characteristics of corresponding tumor foci. METHODS: The present study involved 44 patients undergoing 3.0-Tesla multiparametric MRI before laparoscopic radical prostatectomy. Tracing based on pathological and MRI findings was performed. The relationship between the probability of cancer scaled using the 5-point Likert system and the biological characteristics of corresponding tumor foci was evaluated. RESULTS: A total of 102 tumor foci were identified histologically from the 44 specimens. Of the 102 tumors, 55 were assigned a score based on MRI findings (score 1: n = 3; score 2: n = 3; score 3: n = 16; score 4: n = 11 score 5: n = 22), while 47 were not pointed out on MRI. The tracing study revealed that the proportion of >0.5 cm(3) tumors increased according to the upgrade of Likert scores (score 1 or 2: 33%; score 3: 68.8%; score 4 or 5: 90.9%, χ(2) test, p < 0.0001). The proportion with a Gleason score >7 also increased from scale 2 to scale 5 (scale 2: 0%; scale 3: 56.3%; scale 4: 72.7%; 5: 90.9%, χ(2) test, p = 0.0001). On using score 3 or higher as the threshold of cancer detection on MRI, the detection rate markedly improved if the tumor volume exceeded 0.5 cm(3) (<0.2 cm(3): 10.3%; 0.2-0.5 cm(3): 25%; 0.5-1.0 cm(3): 66.7%; 1.0 < cm(3): 92.1%). CONCLUSIONS: Each Likert scale favobably reflected the corresponding tumor's volume and Gleason score. Our observations show that "score 3 or higher" could be a useful threshold to predict clinically significant carcinoma when considering treatment options.
  • Yuuki Tomiyama, Osamu Manabe, Noriko Oyama-Manabe, Masanao Naya, Hiroyuki Sugimori, Kenji Hirata, Yuki Mori, Hiroyuki Tsutsui, Kohsuke Kudo, Nagara Tamaki, Chietsugu Katoh
    Journal of magnetic resonance imaging : JMRI 42 (3) 754 - 62 1053-1807 2015/09 [Refereed][Not invited]
     
    BACKGROUND: To develop and validate a method for quantifying myocardial blood flow (MBF) using dynamic perfusion magnetic resonance imaging (MBFMRI ) at 3.0 Tesla (T) and compare the findings with those of (15) O-water positron emission tomography (MBFPET ). METHODS: Twenty healthy male volunteers underwent magnetic resonance imaging (MRI) and (15) O-water positron emission tomography (PET) at rest and during adenosine triphosphate infusion. The single-tissue compartment model was used to estimate the inflow rate constant (K1). We estimated the extraction fraction of Gd-DTPA using K1 and MBF values obtained from (15) O-water PET for the first 10 subjects. For validation, we calculated MBFMRI values for the remaining 10 subjects and compared them with the MBFPET values. In addition, we compared MBFMRI values of 10 patients with coronary artery disease with those of healthy subjects. RESULTS: The mean resting and stress MBFMRI values were 0.76 ± 0.10 and 3.04 ± 0.82 mL/min/g, respectively, and showed excellent correlation with the mean MBFPET values (r = 0.96, P < 0.01). The mean stress MBFMRI value was significantly lower for the patients (1.92 ± 0.37) than for the healthy subjects (P < 0.001). CONCLUSION: The use of dynamic perfusion MRI at 3T is useful for estimating MBF and can be applied for patients with coronary artery disease.
  • Susumu Shibasaki, Norihiko Takahashi, Shigenori Homma, Mutsumi Nishida, Tatsushi Shimokuni, Tadashi Yoshida, Hideki Kawamura, Noriko Oyama-Manabe, Kohsuke Kudo, Akinobu Taketomi
    Abdominal imaging 40 (6) 1441 - 50 0942-8925 2015/08 [Refereed][Not invited]
     
    PURPOSE: Although noninvasive and highly informative, transabdominal ultrasonography (US) is not yet an accepted means of staging colorectal cancer preoperatively. This prospective study evaluated the diagnostic accuracy of US in preoperative staging of patients with resectable colon cancers. METHODS: A total of 98 patients with primary colon cancer diagnosed by colonoscopy at our institute between January, 2011 and June, 2014 underwent preoperative ultrasonographic tumor staging. Depth of tumor infiltration (T-stage) was assessed by standard means (i.e., extent of mural involvement), analyzing agreement in US and histopathology determinations. RESULTS: All but two colon cancers (at splenic flexure) were detected by US (98%, 96/98). Compared with histopathology, overall accuracy of US in determining T-stage was 64% (61/96), indicating moderate reproducibility (κ coefficient 0.48; 95% CI 0.35-0.62; p < 0.001). Using a three-tier approach of graded muscularis propria (MP) involvement (Tis/T1, below MP; T2, within MP; and T3/T4, beyond MP), diagnostic agreement increased to 89% (85/96), with good agreement (κ coefficient 0.77; 95% CI 0.64-0.90; p < 0.001). No tumor characteristics or patient demographics influenced diagnostic agreement at any site in the colon. CONCLUSIONS: Given the potential to yield valuable information while limiting patient discomfort, US should be reconsidered as a means of assessing colon cancer.
  • Jonathan A. Goodwin, Kohsuke Kudo, Yutaka Shinohe, Satomi Higuchi, Ikuko Uwano, Fumio Yamashita, Makoto Sasaki
    JOURNAL OF NEUROIMAGING 25 (4) 575 - 581 1051-2284 2015/07 [Refereed][Not invited]
     
    BACKGROUND & PURPOSEIn this work, we demonstrate oxygen extraction fraction (OEF) measurement using 7T MRI with susceptibility-weighted imaging (SWI), in sedated and nonsedated adults. METHODSTen healthy subjects (30.3 4.5 years, 9 men, 1 woman) formed control (n = 5) and sedation groups (n = 5). Midazolam and propofol injection was administered to the same sedation group subjects during 2 different scanning sessions. Two-dimensional SPGR imaging was performed before, during, and twice after (propofol, +10, +30 minutes; midazolam, +10, +40 minutes) conscious sedation. The equivalent procedure was performed with the control group without sedation. After SWI analysis, change in OEF between scans was quantified, and parcelated OEF maps were generated with 77 gray matter (GM)-containing volumes-of-interest (VOIs). RESULTSSignificant decreases in OEF were shown in 14 GM VOIs during sedation relative to the control group, most notably during midazolam sedation (P < .05). In contrast, no significant decrease was observed after 10 minutes and in only 4 VOIs after 40 minutes recovery. CONCLUSIONSignificant change in OEF during conscious sedation using midazolam and propofol could be measured using SWI at 7T in vivo. This may be a potentially useful approach for the noninvasive assessment of OEF in the brain on a clinical basis.
  • Max Wintermark, Marie Luby, Natan M Bornstein, Andrew Demchuk, Jens Fiehler, Kohsuke Kudo, Kennedy R Lees, David S Liebeskind, Patrik Michel, Raul G Nogueira, Mark W Parsons, Makoto Sasaki, Joanna M Wardlaw, Ona Wu, Weiwei Zhang, Guangming Zhu, Steven J Warach
    International journal of stroke : official journal of the International Stroke Society 10 (5) 759 - 62 1747-4930 2015/07 [Refereed][Not invited]
     
    BACKGROUND: To assess the differences across continental regions in terms of stroke imaging obtained for making acute revascularization therapy decisions, and to identify obstacles to participating in randomized trials involving multimodal imaging. METHODS: STroke Imaging Repository (STIR) and Virtual International Stroke Trials Archive (VISTA)-Imaging circulated an online survey through its website, through the websites of national professional societies from multiple countries as well as through email distribution lists from STIR and the above mentioned societies. RESULTS: We received responses from 223 centers (2 from Africa, 38 from Asia, 10 from Australia, 101 from Europe, 4 from Middle East, 55 from North America, 13 from South America). In combination, the sites surveyed administered acute revascularization therapy to a total of 25,326 acute stroke patients in 2012. Seventy-three percent of these patients received intravenous (i.v.) tissue plasminogen activator (tPA), and 27%, endovascular therapy. Vascular imaging was routinely obtained in 79% (152/193) of sites for endovascular therapy decisions, and also as part of standard IV tPA treatment decisions at 46% (92/198) of sites. Modality, availability and use of acute vascular and perfusion imaging before revascularization varied substantially between geographical areas. The main obstacles to participate in randomized trials involving multimodal imaging included: mainly insufficient research support and staff (50%, 79/158) and infrequent use of multimodal imaging (27%, 43/158) . CONCLUSION: There were significant variations among sites and geographical areas in terms of stroke imaging work-up used tomake decisions both for intravenous and endovascular revascularization. Clinical trials using advanced imaging as a selection tool for acute revascularization therapy should address the need for additional resources and technical support, and take into consideration the lack of routine use of such techniques in trial planning.
  • Noriyuki Fujima, Kohsuke Kudo, Akiko Tsukahara, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Khin Khin Tha, Hiroki Shirato
    Journal of magnetic resonance imaging : JMRI 41 (4) 983 - 91 2015/04 [Refereed][Not invited]
     
    PURPOSE: To investigate the feasibility of tumor blood flow (TBF) measurement in head and neck squamous cell carcinoma (HNSCC) using pseudo-continuous arterial spin labeling (pCASL) in a comparison with dynamic contrast-enhanced (DCE) perfusion. MATERIALS AND METHODS: We prospectively scanned 18 patients with HNSCC using 3T magnetic resonance imaging (MRI) with both pCASL and DCE perfusion. Quantitative TBF value in the whole-tumor region of interest (ROI), and regional TBF in the ROIs of the central and peripheral areas in the tumor were respectively measured. Relative TBF value in the whole-tumor ROI was also calculated. We determined the correlation and agreement between each measured TBF by pCASL and DCE perfusion using Pearson's correlation coefficients, intraclass correlation coefficients (ICC), and Bland-Altman analysis. RESULTS: In the whole-tumor ROIs, significant correlation was observed between the absolute TBF values (r = 0.72, P < 0.01), with an ICC of 0.72; moreover, higher correlation was observed in the relative TBF (r = 0.79). The correlation was higher in the peripheral ROI (r = 0.70) than the central ROI (r = 0.65), with an ICC of 0.62 and 0.54, respectively. Bland-Altman plots revealed the underestimation of TBF by pCASL in central ROIs. CONCLUSION: TBF measurement by pCASL was feasible in patients with HNSCC.
  • Noriyuki Fujima, Kohsuke Kudo, Akiko Tsukahara, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Khin Khin Tha, Hiroki Shirato
    Journal of magnetic resonance imaging : JMRI 41 (4) 983 - 91 1053-1807 2015/04 [Refereed][Not invited]
     
    PURPOSE: To investigate the feasibility of tumor blood flow (TBF) measurement in head and neck squamous cell carcinoma (HNSCC) using pseudo-continuous arterial spin labeling (pCASL) in a comparison with dynamic contrast-enhanced (DCE) perfusion. MATERIALS AND METHODS: We prospectively scanned 18 patients with HNSCC using 3T magnetic resonance imaging (MRI) with both pCASL and DCE perfusion. Quantitative TBF value in the whole-tumor region of interest (ROI), and regional TBF in the ROIs of the central and peripheral areas in the tumor were respectively measured. Relative TBF value in the whole-tumor ROI was also calculated. We determined the correlation and agreement between each measured TBF by pCASL and DCE perfusion using Pearson's correlation coefficients, intraclass correlation coefficients (ICC), and Bland-Altman analysis. RESULTS: In the whole-tumor ROIs, significant correlation was observed between the absolute TBF values (r = 0.72, P < 0.01), with an ICC of 0.72; moreover, higher correlation was observed in the relative TBF (r = 0.79). The correlation was higher in the peripheral ROI (r = 0.70) than the central ROI (r = 0.65), with an ICC of 0.62 and 0.54, respectively. Bland-Altman plots revealed the underestimation of TBF by pCASL in central ROIs. CONCLUSION: TBF measurement by pCASL was feasible in patients with HNSCC. J. Magn. Reson. Imaging 2015;41:1-1. © 2014 Wiley Periodicals, Inc.
  • Kenji Ito, Makoto Sasaki, Junko Takahashi, Ikuko Uwano, Fumio Yamashita, Satomi Higuchi, Jonathan Goodwin, Taisuke Harada, Kohsuke Kudo, Yasuo Terayama
    Psychiatry research 231 (3) 346 - 52 0165-1781 2015/03/30 [Refereed][Not invited]
     
    We aimed to determine alterations occurring in the parahippocampal cingulum bundle (PhC) and posterior cingulum bundle (PoC) in patients with mild cognitive impairment (MCI) through analysis of high-resolution multi-parametric diffusion tensor imaging (DTI). Participants comprised 41 patients with MCI (21 AD converters [MCI-C] and 20 non-converters [MCI-NC]), 20 patients with Alzheimer׳s disease (AD), and 26 healthy elderly subjects who underwent prospective examination with high-resolution DTI. An atlas-based regions-of-interest (ROIs) method calculated fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (DA), and radial diffusivity (DR) in the PhC and PoC. For the PhC, FA values showed significant decreases, and MD and DR values showed significantly increases, in the MCI-C and AD groups compared with the healthy controls, although the MCI-C and MCI-NC groups did not differ significantly in these metrics. Conversely, none of the diffusion metrics for the PoC showed a significant difference among the MCI groups and the control groups, although there were significant differences between the AD group and control groups. High-resolution multi-parametric DTI analysis was able to detect substantial changes in diffusion anisotropy and diffusivity in the PhC of patients with MCI who were destined to convert to AD.
  • Kenji Ito, Makoto Sasaki, Junko Takahashi, Ikuko Uwano, Fumio Yamashita, Satomi Higuchi, Jonathan Goodwin, Taisuke Harada, Kohsuke Kudo, Yasuo Terayama
    PSYCHIATRY RESEARCH-NEUROIMAGING 231 (3) 346 - 352 0925-4927 2015/03 [Refereed][Not invited]
     
    We aimed to determine alterations occurring in the parahippocampal cingulum bundle (PhC) and posterior cingulum bundle (PoC) in patients with mild cognitive impairment (MCI) through analysis of high-resolution multi-parametric diffusion tensor imaging (DTI). Participants comprised 41 patients with MCI (21 AD converters [MCI-C] and 20 non-converters IMCI-NCI), 20 patients with Alzheimer's disease (AD), and 26 healthy elderly subjects who underwent prospective examination with highresolution DTI. An atlas-based regions-of-interest (ROls) method calculated fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (DA), and radial diffusivity (DR) in the PhC and PoC. For the PhC. FA values showed significant decreases, and MD and DR values showed significantly increases, in the MCI-C and AD groups compared with the healthy controls, although the MCI-C and MCI-NC groups did not differ significantly in these metrics. Conversely, none of the diffusion metrics for the PoC showed a significant difference among the MCI groups and the control groups, although there were significant differences between the AD group and control groups. High-resolution multi-parametric Dfl analysis was able to detect substantial changes in diffusion anisotropy and diffusivity in the PhC of patients with MCI who were destined to convert to AD. (C) 2015 Elsevier Ireland Ltd. All rights reserved,
  • Junko Takahashi, Toshihide Shibata, Makoto Sasaki, Masako Kudo, Hisashi Yanezawa, Satoko Obara, Kohsuke Kudo, Kenji Ito, Fumio Yamashita, Yasuo Terayama
    Geriatrics & gerontology international 15 (3) 334 - 40 1444-1586 2015/03 [Refereed][Not invited]
     
    AIM: Neuronal degeneration in the locus coeruleus occurs in the early phase of Alzheimer's disease, similar to mild cognitive impairment. The locus coeruleus produces norepinephrine, a deficiency of which causes both memory disturbance and psychological symptoms. Thus, we evaluated signal alterations in the locus coeruleus of patients with Alzheimer's disease and mild cognitive impairment using a high-resolution fast spin-echo T1-weighted imaging. METHODS: A total of 22 patients with Alzheimer's disease, 47 patients with mild cognitive impairment and 26 healthy controls were prospectively examined by high-resolution fast spin-echo T1-weighted imaging at 3 Tesla. Signal intensities in the locus coeruleus were manually measured and expressed relative to those in the adjacent white matter structures as contrast ratios. RESULTS: Locus coeruleus contrast ratios were significantly reduced in patient groups with Alzheimer's disease, mild cognitive impairment that converted to Alzheimer's disease and mild cognitive impairment that did not convert to Alzheimer's disease (1.80-16.09% [median, 9.30%], 3.45-14.84% [median 6.87%] and 3.01-19.19% [median 7.72%], respectively) compared with the healthy control group (6.24-20.94% [median 14.35%]; P < 0.0001). The sensitivity and specificity for discriminating these diseases were 85.0% and 69.2%, respectively, which suggests that this measurement can be carried out reliably. There was no significant difference in the locus coeruleus contrast ratios among the Alzheimer's disease, mild cognitive impairment-converted and mild cognitive impairment-non-converted groups. CONCLUSIONS: High-resolution fast spin-echo T1-weighted imaging can show signal attenuation in the locus coeruleus of patients with Alzheimer's disease or with mild cognitive impairment whose pathology may or may not eventually convert to Alzheimer's disease.
  • Utility of 4D-MRA to Measure Blood Flow Velocity in Cerebral Major Arteries
    Takeo Abumiya, Noriyuki Fujima, Kohsuke Kudo, Yukitomo Ishi, Masayuki Gekka, Hideo Shichinohe, Ken Kazumata, Naoki Nakayama, Kiyohiro Houkin
    STROKE 46 0039-2499 2015/02 [Refereed][Not invited]
  • Noriyuki Miyamoto, Satoshi Yabusaki, Keita Sakamoto, Yasuka Kikuchi, Rie Mimura, Fumi Kato, Noriko Oyama-Manabe, Bunya Takahashi, Takeshi Soyama, Daisuke Abo, Yusuke Sakuhara, Kohsuke Kudo, Hiroki Shirato, Toru Nakamura, Takahiro Tsuchikawa, Keisuke Okamura, Satoshi Hirano
    Japanese journal of radiology 33 (2) 59 - 66 1867-1071 2015/02 [Refereed][Not invited]
     
    PURPOSE: To determine whether the preoperative pancreatic apparent diffusion coefficient (ADC) can be used to predict the development of postoperative pancreatic anastomotic failure (PAF). MATERIALS AND METHODS: We retrospectively examined the cases of 79 patients who underwent pancreatic head resection between January 2010 and October 2013. The patients underwent 1.5-T MR imaging including diffusion-weighted imaging before surgery. The main pancreatic duct diameter (MPD), the pancreatic parenchymal thickness (PT), and the ADC of the pancreatic remnant parenchyma were measured. Two radiologists blinded to the patients' outcomes performed the measurements. The imaging parameters were compared between the patients who developed PAF and those who did not. The cut-off ADC for the development of PAF was calculated with a receiver operating characteristic analysis. RESULTS: The imaging parameters were highly correlated between the two observers. The MPD and PT did not differ significantly among the patients. The mean pancreatic ADCs were significantly higher in the patients with PAF than in those without PAF. An ADC higher than 1.50 × 10(-3) mm(2)/s (Az = 0.719, observer-1) or 1.35 × 10(-3) mm(2)/s (Az = 0.752, observer-2) was optimal for predicting the development of postoperative PAF. CONCLUSION: Measuring the preoperative non-tumorous pancreatic ADC may be useful for the prediction of a postoperative PAF.
  • N Fujima, Y Nakamaru, T Sakashita, A Homma, A Tsukahara, K Kudo, H Shirato
    Dento maxillo facial radiology 44 (9) 20150074 - 20150074 0250-832X 2015 [Refereed][Not invited]
     
    OBJECTIVES: To investigate the diagnostic value of tumour blood flow (TBF) obtained with pseudocontinuous arterial spin labelling for the differentiation of squamous cell carcinoma (SCC) and inverted papilloma (IP) in the nasal or sinonasal cavity. METHODS: We retrospectively analysed the cases of 33 patients with SCC and 8 patients with IP in the nasal or sinonasal cavity. Pseudocontinuous arterial spin labelling scanning was performed for all patients using a 3.0-T MR unit. Quantitative TBF values were measured by two neuroradiologists by respectively delineating the whole-tumour regions of interest, and the mean of them was determined as TBF value in each patient. Additionally, the presence of imaging findings of convoluted cerebriform pattern (CCP) on MR T2 weighted images was determined in all patients. As a subgroup analysis, patients with IP were divided into aggressive and non-aggressive IPs depending on their progression range. First, an intraclass correlation coefficient (ICC) of TBF values between two neuroradiologists was determined. Next, a statistical comparison of the TBF value by a Mann-Whitney U test between the patients with SCC and IP was performed. Additionally, the comparison by an ANOVA with a post hoc test of Tukey's method among the SCC, non-aggressive IP and aggressive IP groups was also performed. If significance was observed, the diagnostic accuracy to differentiate SCCs from IPs was calculated. Diagnostic accuracy by CCP findings alone and by the combination of CCP findings and TBF were also assessed. RESULTS: The ICC of TBF values between two neuroradiologists was 0.82. The mean TBF values in the patients with SCC, all patients with IP, those with aggressive IP and those with non-aggressive IP were 141.2 ± 33.1, 77.8 ± 31.5, 109.4 ± 16.7 and 58.8 ± 19.9 ml 100 g⁻¹ min⁻¹, respectively. A significant difference was observed between SCC and IP (p < 0.001), SCC and non-aggressive IP (p < 0.01) and non-aggressive IP and aggressive IP (p < 0.01). The diagnostic accuracy values obtained with receiver operating characteristic curve analysis for the differentiation of SCC from IP and for SCC from non-aggressive IP were 0.90 and 0.92, respectively. The diagnostic accuracy was elevated (0.95 from 0.88) by adding the TBF value to CCP findings. CONCLUSIONS: The pseudocontinuous arterial spin labelling technique can be a useful non-invasive diagnostic tool to differentiate SCC from IP in nasal or sinonasal cavity.
  • Ikuko Uwano, Tsuyoshi Metoki, Fusako Sendai, Ryoko Yoshida, Kohsuke Kudo, Fumio Yamashita, Satomi Higuchi, Kenji Ito, Taisuke Harada, Jonathan Goodwin, Akira Ogawa, Makoto Sasaki
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 14 (1) 35 - 41 1347-3182 2015 [Refereed][Not invited]
     
    PURPOSE: We investigated sensations experienced by a large number of subjects during magnetic resonance (MR) imaging examinations using a 7-tesla scanner and slow table-feed speed. METHODS: After examinations at 7T, 504 of 508 consecutive subjects completed questionnaires using an 11-point scale to rate 14 potential sensations and symptoms during table movement and stationary positioning of the table. We compared scores among the sensations and between table conditions and the mean values of the scores with those reported in previous studies and examined correlations between the scores and subject characteristics. RESULTS: Vertigo and feelings of curving or leaning in the right or left direction during table movement were experienced frequently and markedly compared to other sensations and sensations experienced when the table was stationary (P < 0.01) and were correlated with subject age and examination time (P < 0.05). However, moderate to severe (scores of 5 to 10) vertigo and a curving/leaning feeling during table movement were noted in only 10.5% (vertigo) and 10.9% (curving/leaning) of subjects, and the mean vertigo score, 1.26, appeared to be substantially lower than that reported in a previous study. Reports of a metallic taste, nausea, and light flashes were significantly rarer and weaker than other sensations (P < 0.05). CONCLUSION: Vertigo and feelings of curving during table movement were the most frequent sensations reported during MR imaging examination at 7T. However, the occurrence and severity were low and mild, presumably because of the slow table-feed speed, which suggests that most patients and volunteers found discomfort at 7T acceptable.
  • Jeff Wang, Fumi Kato, Noriko Oyama-Manabe, Ruijiang Li, Yi Cui, Khin Khin Tha, Hiroko Yamashita, Kohsuke Kudo, Hiroki Shirato
    PloS one 10 (11) e0143308  1932-6203 2015 [Refereed][Not invited]
     
    OBJECTIVES: To determine the added discriminative value of detailed quantitative characterization of background parenchymal enhancement in addition to the tumor itself on dynamic contrast-enhanced (DCE) MRI at 3.0 Tesla in identifying "triple-negative" breast cancers. MATERIALS AND METHODS: In this Institutional Review Board-approved retrospective study, DCE-MRI of 84 women presenting 88 invasive carcinomas were evaluated by a radiologist and analyzed using quantitative computer-aided techniques. Each tumor and its surrounding parenchyma were segmented semi-automatically in 3-D. A total of 85 imaging features were extracted from the two regions, including morphologic, densitometric, and statistical texture measures of enhancement. A small subset of optimal features was selected using an efficient sequential forward floating search algorithm. To distinguish triple-negative cancers from other subtypes, we built predictive models based on support vector machines. Their classification performance was assessed with the area under receiver operating characteristic curve (AUC) using cross-validation. RESULTS: Imaging features based on the tumor region achieved an AUC of 0.782 in differentiating triple-negative cancers from others, in line with the current state of the art. When background parenchymal enhancement features were included, the AUC increased significantly to 0.878 (p<0.01). Similar improvements were seen in nearly all subtype classification tasks undertaken. Notably, amongst the most discriminating features for predicting triple-negative cancers were textures of background parenchymal enhancement. CONCLUSIONS: Considering the tumor as well as its surrounding parenchyma on DCE-MRI for radiomic image phenotyping provides useful information for identifying triple-negative breast cancers. Heterogeneity of background parenchymal enhancement, characterized by quantitative texture features on DCE-MRI, adds value to such differentiation models as they are strongly associated with the triple-negative subtype. Prospective validation studies are warranted to confirm these findings and determine potential implications.
  • Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Akiko Tsukahara, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato
    Magnetic resonance imaging 32 (10) 1206 - 13 0730-725X 2014/12 [Refereed][Not invited]
     
    PURPOSE: To investigate the correlation between perfusion-related parameters obtained with intravoxel incoherent motion (IVIM) and classical perfusion parameters obtained with dynamic contrast-enhanced (DCE) magnetic resonance imaging in patients with head and neck squamous cell carcinoma (HNSCC), and to compare direct and asymptotic fitting, the pixel-by-pixel approach, and a region of interest (ROI)-based approach respectively for IVIM parameter calculation. MATERIALS AND METHODS: Seventeen patients with HNSCC were included in this retrospective study. All magnetic resonance (MR) scanning was performed using a 3T MR unit. Acquisition of IVIM was performed using single-shot spin-echo echo-planar imaging with three orthogonal gradients with 12 b-values (0, 10, 20, 30, 50, 80, 100, 200, 400, 800, 1000, and 2000). Perfusion-related parameters of perfusion fraction 'f' and the pseudo-diffusion coefficient 'D*' were calculated from IVIM data by using least square fitting with the two fitting methods of direct and asymptotic fitting, respectively. DCE perfusion was performed in a total of 64 dynamic phases with a 3.2-s phase interval. The two-compartment exchange model was used for the quantification of tumor blood volume (TBV) and tumor blood flow (TBF). Each tumor was delineated with a polygonal ROI for the calculation of f, f∙D* performed using both the pixel-by-pixel approach and the ROI-based approach. In the pixel-by-pixel approach, after fitting each pixel to obtain f, f∙D* maps, the mean value in the delineated ROI on these maps was calculated. In the ROI-based approach, the mean value of signal intensity was calculated within the ROI for each b-value in IVIM images, and then fitting was performed using these values. Correlations between f in a total of four combinations (direct or asymptotic fitting and pixel-by-pixel or ROI-based approach) and TBV were respectively analyzed using Pearson's correlation coefficients. Correlations between f∙D* and TBF were also similarly analyzed. RESULTS: In all combinations of f and TBV, f∙D* and TBF, there was a significant correlation. In the comparison of f and TBV, a moderate correlation was observed only between f obtained by direct fitting with the pixel-by-pixel approach, whereas a good correlation was observed in the comparisons using the other three combinations. In the comparison of f∙D* and TBF, a good correlation was observed only with f∙D* obtained by asymptotic fitting with the ROI-based approach. In contrast, moderate correlations were observed in the comparisons using the other three combinations. CONCLUSION: IVIM was found to be feasible for the analysis of perfusion-related parameters in patients with HNSCC. Especially, the combination of asymptotic fitting with the ROI-based approach was better correlated with DCE perfusion.
  • Noriyuki Fujima, Kohsuke Kudo, Daisuke Yoshida, Akihiro Homma, Tomohiro Sakashita, Akiko Tsukahara, Khin Khin Tha, Yuri Zaitsu, Satoshi Terae, Hiroki Shirato
    Journal of magnetic resonance imaging : JMRI 40 (4) 920 - 8 1053-1807 2014/10 [Refereed][Not invited]
     
    PURPOSE: To evaluate the feasibility of arterial spin-labeling (ASL) in head and neck cancer for noninvasive measurement of tumor blood flow (TBF), by comparing 1) the TBF change before and after the treatment, and 2) posttreatment TBF and its reduction rate between residual and nonresidual tumors after treatment. MATERIALS AND METHODS: Twenty-two patients with head and neck cancer were evaluated using ASL on 3.0-T magnetic resonance imaging (MRI) before and after nonsurgical treatment. A pulsed ASL sequence with Look–Locker readout was used to calculate quantitative TBF. TBF reduction rates between pre- and posttreatment values were also calculated. Residual tumors were confirmed when present with either histopathologically or clinical follow-up. RESULTS: Pre- and posttreatment mean TBF values were 121.4 ± 27.8 (standard deviation) and 24.9 ± 14.9 mL/100g/min, respectively. Pre- and posttreatment TBF differed significantly. Posttreatment TBF was significantly higher in patients with residual tumors (five patients, 46.9 ± 7.1 mL/100g/min) than in those without (17 patients, 18.4 ± 9.2 mL/100g/min). The TBF reduction rate was significantly lower in patients with residual tumors (0.540.55 ± 0.120.12) than in those without (0.85 ± 0.06). CONCLUSION: ASL allows quantitative assessment of TBF in head and neck cancer. ASL may be useful for noninvasive assessment of tumor viability in head and neck cancer.
  • Fumio Yamashita, Makoto Sasaki, Makoto Saito, Etsuro Mori, Atsushi Kawaguchi, Kohsuke Kudo, Tatsunori Natori, Ikuko Uwano, Kenji Ito, Koichi Saito
    JOURNAL OF NEUROIMAGING 24 (4) 359 - 365 1051-2284 2014/07 [Refereed][Not invited]
     
    OBJECTIVE To determine whether voxel-based morphometry of the cerebrospinal fluid (CSF) space can accurately differentiate iNPH from other related neurological disorders. METHODS Nineteen patients with surgically proven iNPH and 24 patients with Alzheimer's disease (AD), 18 patients with Parkinson's disease (PD), and 14 healthy elderlies were examined. Regions of interest (ROIs) in the ventricular/sylvian (VS) and high convexity/midline (HCM) areas were used in VBM, and differences in CSF volume within these ROIs among the 4 groups were examined. RESULTS The relative CSF volume in the VS-ROI in the iNPH group (.64) was significantly higher than that in the AD, PD, and healthy control groups (.26, .29, and .17, respectively; P < .001), whereas the relative CSF volume in the HCM-ROI was significantly reduced in the iNPH (.10) than in the other (.17, .16, and .16, respectively) groups (P < .001). Furthermore, the ratio of the 2 areas (VS/HCM) was markedly higher in the iNPH (6.87) than in the other (1.65, 1.74, .97, respectively) groups (P < .001), with sensitivity and specificity of .89 and 1.00, respectively. CONCLUSIONS The VBM-based CSF space analysis can detect disproportionate changes in CSF space and differentiate iNPH patients from those with AD or PD and healthy elderlies accurately.
  • Yasuka Kikuchi, Noriko Oyama-Manabe, Masanao Naya, Osamu Manabe, Yuuki Tomiyama, Tsukasa Sasaki, Chietsugu Katoh, Kohsuke Kudo, Nagara Tamaki, Hiroki Shirato
    European radiology 24 (7) 1547 - 56 0938-7994 2014/07 [Refereed][Not invited]
     
    OBJECTIVES: This study introduces a method to calculate myocardium blood flow (MBF) and coronary flow reserve (CFR) using the relatively low-dose dynamic 320-row multi-detector computed tomography (MDCT), validates the method against (15)O-H₂O positron-emission tomography (PET) and assesses the CFRs of coronary artery disease (CAD) patients. METHODS: Thirty-two subjects underwent both dynamic CT perfusion (CTP) and PET perfusion imaging at rest and during pharmacological stress. In 12 normal subjects (pilot group), the calculation method for MBF and CFR was established. In the other 13 normal subjects (validation group), MBF and CFR obtained by dynamic CTP and PET were compared. Finally, the CFRs obtained by dynamic CTP and PET were compared between the validation group and CAD patients (n = 7). RESULTS: Correlation between MBF of MDCT and PET was strong (r = 0.95, P < 0.0001). CFR showed good correlation between dynamic CTP and PET (r = 0.67, P = 0.0126). CFRCT in the CAD group (2.3 ± 0.8) was significantly lower than that in the validation group (5.2 ± 1.8) (P = 0.0011). CONCLUSIONS: We established a method for measuring MBF and CFR with the relatively low-dose dynamic MDCT. Lower CFR was well demonstrated in CAD patients by dynamic CTP. KEY POINTS: • MBF and CFR can be calculated using dynamic CTP with 320-row MDCT. • MBF and CFR showed good correlation between dynamic CTP and PET. • Lower CFR was well demonstrated in CAD patients by dynamic CTP.
  • Kenji Ito, Makoto Sasaki, Masakazu Kobayashi, Kuniaki Ogasawara, Takashi Nishihara, Tetsuhiko Takahashi, Tatsunori Natori, Ikuko Uwano, Fumio Yamashita, Kohsuke Kudo
    JOURNAL OF STROKE & CEREBROVASCULAR DISEASES 23 (5) 1019 - 1023 1052-3057 2014/05 [Refereed][Not invited]
     
    Background: Preoperative assessment of intracranial collateral circulation is helpful in predicting cerebral ischemia during surgical procedures for cervical internal carotid artery (ICA) stenosis. However, magnetic resonance angiography (MRA) and other less-invasive techniques cannot evaluate collateral blood flow because these techniques are nonselective. Hence, by using a newly developed selective MRA technique, we attempted to visualize collaterals via the circle of Willis in patients with ICA stenosis. Methods: Twelve patients who underwent carotid endarterectomy were prospectively examined with a 1.5-T MR scanner. Both selective and nonselective MRA were obtained using a 3-dimensional time-of-flight technique, with or without a cylindrical saturation pulse that suppresses the flow signal from the region of the target ICA. Maximum intensity projection MRA images were generated and compared with digital subtraction angiography (DSA) images. Results: In all patients, the distal flow signal of the ipsilateral ICA was completely suppressed on selective MRA compared with nonselective MRA. In addition, collateral blood flow through the anterior and posterior communicating arteries was visualized in 5 and 2 patients, respectively. These findings corresponded well with the DSA imaging. Conclusions: Selective MRA techniques can readily suppress signals from the distal blood flow of the target artery and visualize the presence of collateral flows through the circle of Willis in patients with cervical ICA stenosis.
  • 西田睦, 柴崎晋, 佐藤恵美, 工藤悠輔, 表原里実, 加藤扶美, 工藤與亮, 下國達志, 高橋典彦, 清水力
    超音波医学 41 S559  1346-1176 2014/04/15 [Not refereed][Not invited]
  • F. Kato, R. Mimura, K. Kudo, N. Manabe, T. Fujiwara, H. Sugimori, M. Hosoda, H. Yamashita, H. Shirato
    Japanese Journal of Clinical Radiology 59 (4) 558 - 562 0009-9252 2014/04 [Refereed][Not invited]
     
    We investigated usefulness of the slice selection gradient reversal (SSGR) method in diffusion weighed imaging (DWI) using 3-tesla breast MRI. Thirty-four women with 42 breast tumors were studied. Image quality and lesion detectability were compared between DWI with and without SSGR. DWI with SSGR had higher image quality with little artifact and higher detectability of the lesions than DWI without SSGR. Image quality and lesion detectability were improved on DWI using SSGR.
  • Tatsunori Natori, Makoto Sasaki, Mitsuharu Miyoshi, Hideki Ohba, Noriyuki Katsura, Mao Yamaguchi, Shinsuke Narumi, Hiroyuki Kabasawa, Kohsuke Kudo, Kenji Ito, Yasuo Terayama
    Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 23 (4) 706 - 11 1052-3057 2014/04 [Refereed][Not invited]
     
    BACKGROUND: Atherosclerotic lesions in intracranial arteries are a leading cause of ischemic stroke. Magnetic resonance angiography (MRA) is often used to assess atherosclerotic changes by detecting luminal narrowing, whereas it cannot directly visualize atherosclerotic lesions. Here, we used a 3-dimensional vessel wall imaging (3D-VWI) technique to evaluate intracranial arterial wall changes in acute stroke. METHODS: Eighteen consecutive patients with acute noncardioembolic stroke in the middle cerebral artery (MCA) territory who were prospectively examined with a 1.5-T magnetic resonance scanner were studied. T1-weighted (T1-W) 3D-VWI was obtained using a flow-sensitized 3D fast-spin echo technique. Wall thickening of MCA that suggests atherosclerotic plaques was visually evaluated and the contrast ratio (CR) of signal intensity of the lesions to that of the corpus callosum was calculated and compared with stenotic changes by MRA. RESULTS: Wall thickenings of the MCA ipsilateral and contralateral to the lesion were observed in almost all patients on 3D-VWI (94.4% and 94.4%, respectively), whereas MRA showed stenotic changes of 50% only in 1 patient (5.9%; P < .001). The CR of the thickened wall in the ipsilateral MCA was significantly higher than that in the contralateral MCA (median, .53 and .45, respectively; P = .028), suggesting of unstable plaques consisting of hemorrhage or lipid. CONCLUSIONS: The T1-W 3D-VWI can provide direct visualization of atherosclerotic lesions of the intracranial arteries in stroke patients, and it can detect signal change suggestive of unstable plaque.
  • Takaaki Beppu, Kazunori Terasaki, Toshiaki Sasaki, Shunrou Fujiwara, Hideki Matsuura, Kuniaki Ogasawara, Koichiro Sera, Noriyuki Yamada, Noriyuki Uesugi, Tamotsu Sugai, Kohsuke Kudo, Makoto Sasaki, Shigeru Ehara, Ren Iwata, Yoshihiro Takai
    Molecular imaging and biology 16 (1) 127 - 35 1536-1632 2014/02 [Refereed][Not invited]
     
    PURPOSE: The aim of this study was to clarify the reliability of positron emission tomography (PET) using a new hypoxic cell tracer, 1-(2-[(18)F]fluoro-1-[hydroxymethyl]ethoxy)methyl-2-nitroimidazole ((18)F-FRP170). PROCEDURES: Twelve patients with glioblastoma underwent (18)F-FRP170 PET before tumor resection. Mean standardized uptake value (SUV) and normalized SUV were calculated at regions within a tumor showing high (high-uptake area) and relatively low (low-uptake area) accumulations of (18)F-FRP170. In these areas, intratumoral oxygen pressure (tpO2) was measured using microelectrodes during tumor resection. RESULTS: Mean tpO2 was significantly lower in the high-uptake area than in the low-uptake area. A significant negative correlation was evident between normalized SUV and tpO2 in the high-uptake area. CONCLUSION: The present findings suggest that high accumulation on (18)F-FRP170 PET represents viable hypoxic tissues in glioblastoma.
  • Ikuko Uwano, Kohsuke Kudo, Fumio Yamashita, Jonathan Goodwin, Satomi Higuchi, Kenji Ito, Taisuke Harada, Akira Ogawa, Makoto Sasaki
    Medical physics 41 (2) 022302 - 022302 0094-2405 2014/02 [Refereed][Not invited]
     
    PURPOSE: To evaluate the performance and efficacy for intensity inhomogeneity correction of various sequences of the human brain in 7T MRI using the extended version of the unified segmentation algorithm. MATERIALS: Ten healthy volunteers were scanned with four different sequences (2D spin echo [SE], 3D fast SE, 2D fast spoiled gradient echo, and 3D time-of-flight) by using a 7T MRI system. Intensity inhomogeneity correction was performed using the "New Segment" module in SPM8 with four different values (120, 90, 60, and 30 mm) of full width at half maximum (FWHM) in Gaussian smoothness. The uniformity in signals in the entire white matter was evaluated using the coefficient of variation (CV); mean signal intensities between the subcortical and deep white matter were compared, and contrast between subcortical white matter and gray matter was measured. The length of the lenticulostriate (LSA) was measured on maximum intensity projection (MIP) images in the original and corrected images. RESULTS: In all sequences, the CV decreased as the FWHM value decreased. The differences of mean signal intensities between subcortical and deep white matter also decreased with smaller FWHM values. The contrast between white and gray matter was maintained at all FWHM values. LSA length was significantly greater in corrected MIP than in the original MIP images. CONCLUSIONS: Intensity inhomogeneity in 7T MRI can be successfully corrected using SPM8 for various scan sequences.
  • Jeff Wang, Fumi Kato, Kohsuke Kudo, Hiroko Yamashita, Hiroki Shirato
    Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 8539 334 - 340 1611-3349 2014 [Refereed][Not invited]
     
    Early classification of breast cancers by molecular subtype allows for expeditious characterization of the disease and selection of appropriate treatment options. This ability is especially a concern for "triple- negative" cancers, which lack expression of the three cell surface receptors that most breast cancer hormonal therapies target, tend to be the most aggressive/metastatic compared to other subtypes, have lymph node involvement at diagnoses, and have relatively poor prognoses. In this study, we aim to develop predictive models using Dynamic Contrast-Enhanced (DCE) MRI-extracted features to identify triple-negative cancers and axillary lymph node metastasis at the time of diagnostic imaging. Using only morphological, pharmacokinetic, densitometric, statistical, textural, and textural kinetic features obtained from DCE-MRI, we were able to classify 91.3% of 69 lesions correctly for triple-negative status with a sensitivity of 55.6%, a specificity of 96.7, and an AUC of 0.889 71.6% of lesions correctly for lymph node metastasis with a sensitivity of 50.0%, a specificity of 82.2%, and an AUC of 0.677. © 2014 Springer International Publishing.
  • Gen Haba, Hidekazu Nishigori, Makoto Sasaki, Koujiro Tohyama, Kohsuke Kudo, Yutaka Matsumura, Toru Sugiyama, Keisuke Kagami, Yu Tezuka, Atsushi Sanbe, Hideo Nishigori
    Psychopharmacology 231 (1) 221 - 30 0033-3158 2014/01 [Refereed][Not invited]
     
    RATIONALE AND OBJECTIVES: The effects of low thyroid hormone level during embryogenesis on MRI of the brain and social behaviors of hatchlings were examined using "fertilized hen's egg-embryo-chick" system. METHODS AND RESULTS: Control and hatchlings treated with methimazole (20 μmol/egg), which hatched 3 days later than controls were examined. The results are as follows: 1. The MRI examination of the midsagittal section of the brain on hatch day showed that the sizes, by T1- and ADC values by diffusion-weighted images, of the optic lobe and cerebellum of the MMI-hatchlings were significantly bigger than those of the controls. 2. The social behaviors on post-hatch day 3 were based on the following tests: (a) Aggregation test: The speed of four chicks, individually isolated by cardboard barriers in a box, to make a group upon the removal of barriers. (b) Belongingness tests: The speed of a chick isolated at a corner to join the group of three chicks placed at the opposite corner. (c) Vocalization test: The number of decibel produced by a chick isolated at a corner using a sound meter. These tests demonstrated that MMI-hatchlings took longer times and had weaker vocalization than the controls, significantly. 3. Upregulation of THRβ mRNA after MMI treatment suggested that THR was necessary for cerebellum development. CONCLUSIONS: The MMI exposure during the last week of embryogenesis possibly delayed the myelination of certain brain regions and impaired the social behaviors of hatchlings. The chick embryos can be easily induced with hypothyroidism without maternal influences, and the hatchling's behaviors were analyzed using a video camera. The present method will be useful for assessing the effects of unfavorable influences during embryogenesis on social behaviors in later life.
  • Kohsuke Kudo, Timothé Boutelier, Fabrice Pautot, Kaneyoshi Honjo, Jin-Qing Hu, Hai-Bin Wang, Katsuya Shintaku, Ikuko Uwano, Makoto Sasaki
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 13 (1) 45 - 50 1347-3182 2014 [Refereed][Not invited]
     
    PURPOSE: We compared the performances of a Bayesian estimation method and oscillation index singular value decomposition (oSVD) deconvolution for predicting final infarction using data previously obtained from 10 cynomolgus monkeys with permanent unilateral middle cerebral artery (MCA) occlusion. METHODS: We conducted baseline perfusion-weighted imaging 3 hours after MCA occlusion and generated time to peak, first moment of transit, cerebral blood flow, cerebral blood volume, and mean transit time maps using Bayesian and oSVD methods. Final infarct volume was determined by follow-up diffusion-weighted imaging (DWI) scanned 47 hours after MCA occlusion and from histological specimens. We used a region growing technique with various thresholds to determine perfusion abnormality volume. The best threshold was defined when the mean perfusion volume matched the mean final infarct volume, and Pearson's correlation coefficients (r) and intraclass correlations (ICC) were calculated between perfusion abnormality and final infarct volume at that threshold. These coefficients were compared between Bayesian and oSVD using Wilcoxon's signed rank test. P-value < 0.05 was considered a statistically significant difference. RESULTS: The Pearson's correlation coefficients were larger but not significantly different for the Bayesian technique than oSVD in 4 of 5 perfusion maps when final infarct was determined by specimen volume (P = 0.104). When final infarct volume was defined by DWI volume, all perfusion maps had a significantly higher correlation coefficient by Bayesian technique than oSVD (P = 0.043). For ICC, all perfusion maps had higher value in Bayesian than oSVD calculation, and significant differences were observed both on specimen- and DWI-defined volumes (P = 0.043 for both). CONCLUSION: The Bayesian method is more reliable than oSVD deconvolution in estimating final infarct volume.
  • Makoto Sasaki, Kohsuke Kudo, Soren Christensen, Fumio Yamashita, Jonathan Goodwin, Satomi Higuchi, Akira Ogawa
    Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association 22 (8) 1212 - 5 1052-3057 2013/11 [Refereed][Not invited]
     
    Perfusion computed tomography and perfusion-weighted magnetic resonance imaging are used to evaluate the extent of the area with ischemic penumbra; however, different parameters, algorithms, and software packages show significant discrepancies in the size of perfusion abnormalities, which should be minimized. Recently, cross-validation studies were performed using digital phantoms and have elucidated the precision and reliability of various penumbral imaging techniques. These research initiatives can promote further multicenter trials on recanalization therapies by providing accurate inclusion/exclusion criteria for appropriate patient selection.
  • Yuiko Sato, Kenji Ito, Kuniaki Ogasawara, Makoto Sasaki, Kohsuke Kudo, Toshiyuki Murakami, Takamasa Nanba, Hideaki Nishimoto, Kenji Yoshida, Masakazu Kobayashi, Yoshitaka Kubo, Tomohiko Mase, Akira Ogawa
    Neurosurgery 73 (4) 592 - 8 0148-396X 2013/10 [Refereed][Not invited]
     
    BACKGROUND: Carotid endarterectomy (CEA) might improve cognitive function. Fractional anisotropy (FA) values in the cerebral white matter derived from diffusion tensor magnetic resonance imaging (DTI) correlate with cognitive function in patients with various central nervous system diseases. OBJECTIVE: To use tract-based spatial statistics to determine whether postoperative changes of FA values in the cerebral white matter derived from DTI are associated with cognitive improvement after uncomplicated CEA. METHODS: In 80 patients undergoing CEA for ipsilateral internal carotid artery stenosis (≥70%), FA values in the cerebral white matter were derived from DTI before and 1 month after surgery and were analyzed by using tract-based spatial statistics. Neuropsychological testing, consisting of the Wechsler Adult Intelligence Scale Revised, the Wechsler Memory Scale and the Rey-Osterreith Complex Figure test, was also performed preoperatively and after the first postoperative month. RESULTS: Based on the neuropsychological assessments, 11 (14%) patients were defined as having postoperatively improved cognition. The difference between the 2 mean FA values (postoperative values minus preoperative values) in the cerebral hemisphere ipsilateral to surgery was significantly associated with postoperative cognitive improvement (95% confidence intervals, 2.632-9.877; P = .008). White matter FA values in patients with postoperative cognitive improvement were significantly increased after surgery in the whole ipsilateral cerebral hemisphere, in the contralateral anterior cerebral artery territory, and in the watershed zone between the contralateral anterior and middle cerebral arteries. CONCLUSION: Postoperative increase in cerebral white matter FA on DTI is associated with cognitive improvement after uncomplicated CEA.
  • Makoto Sasaki, Kohsuke Kudo, Timothé Boutelier, Fabrice Pautot, Soren Christensen, Ikuko Uwano, Jonathan Goodwin, Satomi Higuchi, Kenji Ito, Fumio Yamashita
    Neuroradiology 55 (10) 1197 - 203 0028-3940 2013/10 [Refereed][Not invited]
     
    INTRODUCTION: A new deconvolution algorithm, the Bayesian estimation algorithm, was reported to improve the precision of parametric maps created using perfusion computed tomography. However, it remains unclear whether quantitative values generated by this method are more accurate than those generated using optimized deconvolution algorithms of other software packages. Hence, we compared the accuracy of the Bayesian and deconvolution algorithms by using a digital phantom. METHODS: The digital phantom data, in which concentration-time curves reflecting various known values for cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and tracer delays were embedded, were analyzed using the Bayesian estimation algorithm as well as delay-insensitive singular value decomposition (SVD) algorithms of two software packages that were the best benchmarks in a previous cross-validation study. Correlation and agreement of quantitative values of these algorithms with true values were examined. RESULTS: CBF, CBV, and MTT values estimated by all the algorithms showed strong correlations with the true values (r = 0.91-0.92, 0.97-0.99, and 0.91-0.96, respectively). In addition, the values generated by the Bayesian estimation algorithm for all of these parameters showed good agreement with the true values [intraclass correlation coefficient (ICC) = 0.90, 0.99, and 0.96, respectively], while MTT values from the SVD algorithms were suboptimal (ICC = 0.81-0.82). CONCLUSIONS: Quantitative analysis using a digital phantom revealed that the Bayesian estimation algorithm yielded CBF, CBV, and MTT maps strongly correlated with the true values and MTT maps with better agreement than those produced by delay-insensitive SVD algorithms.
  • Max Wintermark, Gregory W Albers, Joseph P Broderick, Andrew M Demchuk, Jochen B Fiebach, Jens Fiehler, James C Grotta, Gary Houser, Tudor G Jovin, Kennedy R Lees, Michael H Lev, David S Liebeskind, Marie Luby, Keith W Muir, Mark W Parsons, Rüdiger von Kummer, Joanna M Wardlaw, Ona Wu, Albert J Yoo, Andrei V Alexandrov, Jeffry R Alger, Richard I Aviv, Roland Bammer, Jean-Claude Baron, Fernando Calamante, Bruce C V Campbell, Trevor C Carpenter, Søren Christensen, William A Copen, Colin P Derdeyn, E Clarke Haley Jr, Pooja Khatri, Kohsuke Kudo, Maarten G Lansberg, Lawrence L Latour, Ting-Yim Lee, Richard Leigh, Weili Lin, Patrick Lyden, Grant Mair, Bijoy K Menon, Patrik Michel, Robert Mikulik, Raul G Nogueira, Leif Ostergaard, Salvador Pedraza, Christian H Riedel, Howard A Rowley, Pina C Sanelli, Makoto Sasaki, Jeffrey L Saver, Pamela W Schaefer, Peter D Schellinger, Georgios Tsivgoulis, Lawrence R Wechsler, Philip M White, Greg Zaharchuk, Osama O Zaidat, Stephen M Davis, Geoffrey A Donnan, Anthony J Furlan, Werner Hacke, Dong-Wha Kang, Chelsea Kidwell, Vincent N Thijs, Götz Thomalla, Steven J Warach
    Stroke 44 (9) 2628 - 39 0039-2499 2013/09 [Refereed][Not invited]
  • Max Wintermark, Jens Fiehler, Kohsuke Kudo, David S. Liebeskind, Marie Luby, Patrik Michel, Raul Nogueira, Mark Parsons, Makoto Sasaki, Joanna Wardlaw, Ona Wu, Weiwei Zhang, Guangming Zhu, Steven Warach
    Stroke 44 (8) 2091  0039-2499 2013/08 [Refereed][Not invited]
  • Kimihiro Ogisu, Kohsuke Kudo, Makoto Sasaki, Ken Sakushima, Ichiro Yabe, Hidenao Sasaki, Satoshi Terae, Mitsuhiro Nakanishi, Hiroki Shirato
    Neuroradiology 55 (6) 719 - 24 0028-3940 2013/06 [Refereed][Not invited]
     
    INTRODUCTION: Neuromelanin-sensitive MRI has been reported to be used in the diagnosis of Parkinson's disease (PD), which results from loss of dopamine-producing cells in the substantia nigra pars compacta (SNc). In this study, we aimed to apply a 3D turbo field echo (TFE) sequence for neuromelanin-sensitive MRI and to evaluate the diagnostic performance of semi-automated method for measurement of SNc volume in patients with PD. METHODS: We examined 18 PD patients and 27 healthy volunteers (control subjects). A 3D TFE technique with off-resonance magnetization transfer pulse was used for neuromelanin-sensitive MRI on a 3T scanner. The SNc volume was semi-automatically measured using a region-growing technique at various thresholds (ranging from 1.66 to 2.48), with the signals measured relative to that for the superior cerebellar peduncle. Receiver operating characteristic (ROC) analysis was performed at all thresholds. Intra-rater reproducibility was evaluated by intraclass correlation coefficient (ICC). RESULTS: The average SNc volume in the PD group was significantly smaller than that in the control group at all the thresholds (P < 0.01, student t test). At higher thresholds (>2.0), the area under the curve of ROC (Az) increased (0.88). In addition, we observed balanced sensitivity and specificity (0.83 and 0.85, respectively). At lower thresholds, sensitivity tended to increase but specificity reduced in comparison with that at higher thresholds. ICC was larger than 0.9 when the threshold was over 1.86. CONCLUSIONS: Our method can distinguish the PD group from the control group with high sensitivity and specificity, especially for early stage of PD.
  • Chigumi Ohtsuka, Makoto Sasaki, Kanako Konno, Mizuho Koide, Kanako Kato, Junko Takahashi, Satoshi Takahashi, Kohsuke Kudo, Fumio Yamashita, Yasuo Terayama
    Neuroscience letters 541 93 - 8 0304-3940 2013/04/29 [Refereed][Not invited]
     
    Neuromelanin-sensitive magnetic resonance imaging is able to visualize changes associated with neuronal loss in the substantia nigra pars compacta (SNc) and locus coeruleus (LC) in patients with Parkinson's disease (PD). However, the diagnostic accuracy of this technique in the early stages of PD remains unknown. Therefore, changes in the SNc and LC observed using neuromelanin imaging were evaluated in patients with early PD. The signal intensities of the lateral, central, and medial parts of the SNc and that of the LC were measured, and the contrast ratios (CRs) were calculated against the adjacent white matter structures. CRs in the lateral part of the SNc and in the LC were significantly reduced in the early PD group when compared with the controls. Sensitivities and specificities in discriminating early PD patients from healthy controls were 73% and 87% in lateral SNc and 82% and 90% in LC, respectively. Neuromelanin imaging can depict signal alterations in the lateral part of the SNc and in the LC in patients with PD, even in its early stage, and can discriminate between these patients and healthy individuals with high sensitivities and specificities.
  • Ikuko Uwano, Makoto Sasaki, Kohsuke Kudo, Shunrou Fujiwara, Mao Yamaguchi, Ayumi Saito, Kuniaki Ogasawara, Akira Ogawa
    Journal of neuroimaging : official journal of the American Society of Neuroimaging 23 (2) 197 - 201 1051-2284 2013/04 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Diffusion anisotropy color-coded maps of cerebral white matter can be generated from orthogonal anisotropic diffusion-weighted imaging (DWI) using the three-dimensional anisotropy contrast (3DAC) technique, but its precision has not been fully validated. Hence, we attempted to determine whether 3DAC is comparable to a diffusion tensor imaging (DTI) color map. METHODS: We examined 15 healthy individuals and generated color-coded maps using 3DAC as well as using primary eigenvector (e1) and fractional anisotropy (FA) from identical DTI datasets. The difference in the direction of the 3DAC vector from e1 (θ) in cerebral white matter was evaluated. Correlations between θ and FA or obliqueness of e1 were also examined. RESULTS: In cerebral white matter, θ had significantly negative and positive correlations with FA values and e1 obliqueness, respectively. Among white matter tracts, the pyramidal tract, cingulum, and corpus callosum, which had significantly high FA and/or low obliqueness, exhibited similar coloration and significantly smaller θ (4.4° ± 1.6°, 9.3° ± 2.8°, and 11.2° ± 1.1°, respectively) than the entire white matter (13.9° ± 1.1°). CONCLUSIONS: The 3DAC could visualize directional information of white matter tracts as precisely DTI-based color maps did, particularly when FA was large and/or e1 directions were orthogonal.
  • Kohsuke Kudo, Soren Christensen, Makoto Sasaki, Leif Østergaard, Hiroki Shirato, Kuniaki Ogasawara, Max Wintermark, Steven Warach
    Radiology 267 (1) 201 - 11 0033-8419 2013/04 [Refereed][Not invited]
     
    PURPOSE: To design a digital phantom data set for computed tomography (CT) perfusion and perfusion-weighted imaging on the basis of the widely accepted tracer kinetic theory in which the true values of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and tracer arrival delay are known and to evaluate the accuracy and reliability of postprocessing programs using this digital phantom. MATERIALS AND METHODS: A phantom data set was created by generating concentration-time curves reflecting true values for CBF (2.5-87.5 mL/100 g per minute), CBV (1.0-5.0 mL/100 g), MTT (3.4-24 seconds), and tracer delays (0-3.0 seconds). These curves were embedded in human brain images. The data were analyzed by using 13 algorithms each for CT and magnetic resonance (MR), including five commercial vendors and five academic programs. Accuracy was assessed by using the Pearson correlation coefficient (r) for true values. Delay-, MTT-, or CBV-dependent errors and correlations between time to maximum of residue function (Tmax) were also evaluated. RESULTS: In CT, CBV was generally well reproduced (r > 0.9 in 12 algorithms), but not CBF and MTT (r > 0.9 in seven and four algorithms, respectively). In MR, good correlation (r > 0.9) was observed in one-half of commercial programs, while all academic algorithms showed good correlations for all parameters. Most algorithms had delay-dependent errors, especially for commercial software, as well as CBV dependency for CBF or MTT calculation and MTT dependency for CBV calculation. Correlation was good in Tmax except for one algorithm. CONCLUSION: The digital phantom readily evaluated the accuracy and characteristics of the CT and MR perfusion analysis software. All commercial programs had delay-induced errors and/or insufficient correlations with true values, while academic programs for MR showed good correlations with true values. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112618/-/DC1.
  • Noriko Oyama-Manabe, Takahiro Sato, Ichizo Tsujino, Kohsuke Kudo, Osamu Manabe, Fumi Kato, Nael F Osman, Satoshi Terae
    The international journal of cardiovascular imaging 29 (2) 371 - 8 1569-5794 2013/02 [Refereed][Not invited]
     
    The aim of this study was to explore whether the regional peak longitudinal (LS) and circumferential strains (CS) at the right ventricular (RV) free wall could be used to identify global RV dysfunction in relation to RV ejection fraction (RVEF) and plasma concentration of brain natriuretic peptide (BNP) in pulmonary hypertension (PH). A total of 37 consecutive patients diagnosed with PH and 13 healthy control subjects were included. Fast strain encoded and routine cine MRI was performed. The LS and CS at three RV levels were quantified and their relations with RVEF and BNP were investigated. Receiver operating characteristic (ROC) analysis was employed to assess the diagnostic utility of strain encoded MRI for the detection of low RVEF. Significant correlations with LS were observed for RVEF and BNP. Compared to CS, LS showed better correlation with RVEF. The mid-ventricular level of RV was the most sensitive site for evaluation of RV dysfunction. According to our ROC analysis, LS showed higher sensitivity and specificity to detect low RVEF. Compared to CS, LS showed stronger correlations with RVEF and BNP and could be a good detector of RV dysfunction in PH.
  • Makoto Sasaki, Fumio Yamashita, Kohsuke Kudo
    Current Clinical Neurology 44 159 - 164 1559-0585 2013 [Refereed][Not invited]
     
    Neuromelanin, a black pigment present in dopaminergic and noradrenergic neurons in the substantia nigra pars compacta (SNc) and locus ceruleus (LC), has paramagnetic T1-shortening effects. Conventional magnetic resonance imaging (cMRI) techniques fail to depict the contrast generated by neuromelanin, but there are some neuromelanin-sensitive techniques that allow direct visualization of the SNc and LC as evident high-signal areas. In Parkinson disease, neuromelanin-related signals from the SNc and LC are attenuated suggesting neuronal loss in both these nuclei. In other neurodegenerative and psychiatric disorders, signal alterations of SNc and/or LC can also be shown. Neuromelanin-sensitive MRI is a promising technique to assess changes in these nuclei that occur in Parkinson disease and other related disorders.
  • S. Narumi, M. Sasaki, H. Ohba, K. Ogasawara, M. Kobayashi, J. Hitomi, K. Mori, K. Ohura, M. Yamaguchi, K. Kudo, Y. Terayama
    AMERICAN JOURNAL OF NEURORADIOLOGY 34 (1) 191 - 197 0195-6108 2013/01 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Electrocardiographic gating, commonly used in MR carotid plaque imaging, can negatively affect intraplaque contrast if the TR is inappropriate. The present study aimed to determine whether a non-gated technique with appropriate TRs can accurately evaluate intraplaque characteristics in specimens excised by CEA. MATERIALS AND METHODS: We prospectively examined 40 consecutive patients who underwent CEA (59-82 years of age) by using a 1.5T scanner. Axial T1WI with a TR of 500 ms and PDWI and T2WI with a TR of 3000 ms with a self-navigated rotating-blade scan instead of cardiac gating were obtained. Signal intensities of the plaque and adjacent muscle were measured, and the CR on T1WI, PDWI, and T2WI as well as the gray-scale median on US were correlated with the pathologic findings of the CEA specimens. RESULTS: On T1WI, the CRs of the carotid plaques differed significantly among groups in which the main components were histologically confirmed as fibrous tissue, lipid/necrosis, and hemorrhage (0.54-1.17,1.16-1.53, and 1.40-2.29, respectively). The sensitivity and specificity for discriminating lipid/necrosis/hemorrhage from fibrous tissue were 96% and 100%, respectively. On T2WI, the CRs of plaques with lipid/necrosis were significantly higher than those of other groups, but the CRs on PDWI and the gray-scale median on US were not significantly different among the groups. CONCLUSIONS: Non-gated MR plaque imaging, particularly T1WI, can readily predict the intraplaque main components of the carotid artery with high sensitivity and specificity.
  • Ayumi Saito, Makoto Sasaki, Kuniaki Ogasawara, Masakazu Kobayashi, Jiro Hitomi, Shinsuke Narumi, Hideki Ohba, Mao Yamaguchi, Kohsuke Kudo, Yasuo Terayama
    Neuroradiology 54 (11) 1187 - 94 0028-3940 2012/11 [Refereed][Not invited]
     
    INTRODUCTION: Several magnetic resonance (MR) imaging techniques are used to examine atherosclerotic plaque of carotid arteries; however, the best technique for visualizing intraplaque characteristics has yet to be determined. Here, we directly compared four kinds of T1-weighted (T1W) imaging techniques with pathological findings in patients with carotid stenosis. METHODS: A total of 31 patients who were candidates for carotid endarterectomy were prospectively examined using a 1.5-T MRI scanner, which produced four kinds of T1W images, including non-gated spin echo (SE), cardiac-gated black-blood (BB) fast-SE (FSE), magnetization-prepared rapid acquisition with gradient echo (MPRAGE), and source image of three-dimensional time-of-flight MR angiography (SI-MRA). The signal intensity of the carotid plaque was manually measured, and the contrast ratio (CR) against the adjacent muscle was calculated. CRs from the four imaging techniques were compared to each other and correlated with histopathological specimens. RESULTS: CRs of the carotid plaques mainly containing fibrous tissue, lipid/necrosis, and hemorrhage were significantly different with little overlaps (range: 0.92-1.15, 1.22-1.52, and 1.55-2.30, respectively) on non-gated SE. However, BB-FSE showed remarkable overlaps among the three groups (0.89-1.10, 1.07-1.23, and 1.01-1.42, respectively). MPRAGE could discriminate fibrous plaques from hemorrhagic plaques but not from lipid/necrosis-rich plaques: (0.77-1.07, 1.45-2.43, and 0.85-1.42, respectively). SI-MRA showed the same tendencies (1.01-1.39, 1.45-2.57, and 1.12-1.39, respectively). CONCLUSION: Among T1W MR imaging techniques, non-gated SE images can more accurately characterize intraplaque components in patients who underwent CEA when compared with cardiac-gated BB-FSE, MPRAGE, and SI-MRA images.
  • Mao Yamaguchi, Makoto Sasaki, Hideki Ohba, Kiyofumi Mori, Shinsuke Narumi, Noriyuki Katsura, Kazumasa Ohura, Kohsuke Kudo, Yasuo Terayama
    Neuroradiology 54 (9) 939 - 45 0028-3940 2012/09 [Refereed][Not invited]
     
    INTRODUCTION: Cilostazol, an antiplatelet agent, is reported to induce the regression of atherosclerotic changes. However, its effects on carotid plaques are unknown. Hence, we quantitatively investigated the changes that occur within carotid plaques during cilostazol administration using three-dimensional (3D) ultrasonography (US) and non-gated magnetic resonance (MR) plaque imaging. METHODS: We prospectively examined 16 consecutive patients with carotid stenosis. 3D-US and T1-weighted MR plaque imaging were performed at baseline and 6 months after initiating cilostazol therapy (200 mg/day). We measured the volume and grayscale median (GSM) of the plaques from 3D-US data. We also calculated the contrast ratio (CR) of the carotid plaque against the adjacent muscle and areas of the intraplaque components: fibrous tissue, lipid, and hemorrhage components. RESULTS: The plaque volume on US decreased significantly (median at baseline and 6 months, 0.23 and 0.21 cm(3), respectively; p = 0.03). In the group exhibiting a plaque volume reduction of more than 10%, GSM on US increased significantly (24.8 and 71.5, respectively; p = 0.04) and CR on MRI decreased significantly (1.13 and 1.04, respectively; p = 0.02). In this group, in addition, the percent area of the fibrous component on MRI increased significantly (68.6% and 79.4%, respectively; p = 0.02), while those of the lipid and hemorrhagic components decreased (24.9% and 20.5%, respectively; p = 0.12) (1.0% and 0.0%, respectively; p = 0.04). There were no substantial changes in intraplaque characteristics in either US or MRI in the other group. CONCLUSIONS: 3D-US and MR plaque imaging can quantitatively detect changes in the size and composition of carotid plaques during cilostazol therapy.
  • Carlos Leiva-Salinas, James M Provenzale, Kohsuke Kudo, Makoto Sasaki, Max Wintermark
    Neuroradiology 54 (9) 907 - 18 0028-3940 2012/09 [Refereed][Not invited]
     
    The five questions answered in this article revolve around the different parameters resulting from perfusion imaging processing, and this clarifies the frequently confusing terminology used to describe these parameters. More specifically, the article discusses the different imaging techniques and main mathematical models behind perfusion imaging, reviews the perfusion attributes of brain tissue, and proposes a standardized parameter terminology to facilitate understanding and avoid common misinterpretations.
  • [Neuroimaging using ultrahigh-field magnetic resonance imaging at 7 tesla: current concepts].
    Makoto Sasaki, Kohsuke Kudo, Ikuko Uwano, Hiroyuki Kabasawa, Tsuyoshi Matsuda
    Brain and nerve = Shinkei kenkyu no shinpo 64 (9) 1057 - 62 1881-6096 2012/09 [Refereed][Not invited]
     
    The introduction of ultrahigh-field MRI at 7 tesla (7T) has increased the interest in the use of neuroimaging techniques in clinical research. The high signal-to-noise ratio and profound susceptibility effect at 7T can remarkably improve the spatial resolution and image contrast of structural imaging, susceptibility imaging, and functional imaging techniques, whereas the heating effects of the radio frequency and the inhomogeneities of the local magnetic field can have substantial negative effects on parameter setting, acquisition time, and image quality. T1 prolongation at 7T can improve the enhancement effects of gadolinium agents and the inflow effects on MR angiography and arterial spin labeling. Ultrahigh-field MRI is expected to have a high clinical impact in the near future; however, further technological advances tailored to ultrahigh-field systems as well as the accumulation of scientific evidence will be needed to establish its clinical significance.
  • Timothé Boutelier, Koshuke Kudo, Fabrice Pautot, Makoto Sasaki
    IEEE transactions on medical imaging 31 (7) 1381 - 95 2012/07 [Refereed][Not invited]
     
    A delay-insensitive probabilistic method for estimating hemodynamic parameters, delays, theoretical residue functions, and concentration time curves by computed tomography (CT) and magnetic resonance (MR) perfusion weighted imaging is presented. Only a mild stationarity hypothesis is made beyond the standard perfusion model. New microvascular parameters with simple hemodynamic interpretation are naturally introduced. Simulations on standard digital phantoms show that the method outperforms the oscillating singular value decomposition (oSVD) method in terms of goodness-of-fit, linearity, statistical and systematic errors on all parameters, especially at low signal-to-noise ratios (SNRs). Delay is always estimated sharply with user-supplied resolution and is purely arterial, by contrast to oSVD time-to-maximum TMAX that is very noisy and biased by mean transit time (MTT), blood volume, and SNR. Residue functions and signals estimates do not suffer overfitting anymore. One CT acute stroke case confirms simulation results and highlights the ability of the method to reliably estimate MTT when SNR is low. Delays look promising for delineating the arterial occlusion territory and collateral circulation.
  • Shunrou Fujiwara, Takaaki Beppu, Hideaki Nishimoto, Katsumi Sanjo, Atsuhiko Koeda, Kiyoshi Mori, Kohsuke Kudo, Makoto Sasaki, Kuniaki Ogasawara
    Neuroradiology 54 (7) 681 - 9 0028-3940 2012/07 [Refereed][Not invited]
     
    INTRODUCTION: The present study aimed to detect the main regions of cerebral white matter (CWM) showing damage in the subacute phase for CO-poisoned patients with chronic neurological symptoms using voxel-based analysis (VBA) with diffusion tensor imaging (DTI). METHODS: Subjects comprised 22 adult CO-poisoned patients and 16 age-matched healthy volunteers as controls. Patients were classified into patients with transient acute symptoms only (group A) and patients with chronic neurological symptoms (group S). In all patients, DTI covering the whole brain was performed with a 3.0-T magnetic resonance imaging system at 2 weeks after CO exposure. As procedures for VBA, all fractional anisotropy (FA) maps obtained from DTI were spatially normalized, and FA values for all voxels in the whole CWM on normalized FA maps were statistically compared among the two patient groups and controls. RESULTS: Voxels with significant differences in FA were detected at various regions in comparisons between groups S and A and between group S and controls. In these comparisons, more voxels were detected in deep CWM, including the centrum semiovale, than in other regions. A few voxels were detected between group A and controls. Absolute FA values in the centrum semiovale were significantly lower in group S than in group A or controls. CONCLUSIONS: VBA demonstrated that CO-poisoned patients with chronic neurological symptoms had already suffered damage to various CWM regions in the subacute phase. In these regions, the centrum semiovale was suggested to be the main region damaged in the subacute phase after CO inhalation.
  • Taro Hanada, Akihiko Ishikuro, Yasushi Hasegawa, Masafumi Shimamoto, Masaaki Kobayashi, Kohsuke Kudo
    Respiratory investigation 50 (2) 62 - 5 2212-5345 2012/06 [Refereed][Not invited]
     
    Two cases of spontaneous epidural emphysema that occurred during asthmatic attacks in a 13-year-old and a 15-year-old are reported here. Epidural emphysema was diagnosed in both cases by using computed tomography (CT), and in 1 case by using magnetic resonance imaging (MRI). Neither patient had neurological findings. Both patients were discharged with no respiratory difficulties. It is generally believed that a diagnosis of epidural emphysema can only be made on CT. In this report, MRI was used to make the diagnosis of subdural emphysema, and it demonstrated that the air was localized within the epidural fat.
  • Ikuko Uwano, Kohsuke Kudo, Makoto Sasaki, Soren Christensen, Leif Østergaard, Kuniaki Ogasawara, Akira Ogawa
    Neuroradiology 54 (5) 467 - 74 0028-3940 2012/05 [Refereed][Not invited]
     
    INTRODUCTION: Computed tomography perfusion (CTP) and magnetic resonance perfusion (MRP) are expected to be usable for ancillary tests of brain death by detection of complete absence of cerebral perfusion; however, the detection limit of hypoperfusion has not been determined. Hence, we examined whether commercial software can visualize very low cerebral blood flow (CBF) and cerebral blood volume (CBV) by creating and using digital phantoms. METHODS: Digital phantoms simulating 0-4% of normal CBF (60 mL/100 g/min) and CBV (4 mL/100 g/min) were analyzed by ten software packages of CT and MRI manufacturers. Region-of-interest measurements were performed to determine whether there was a significant difference between areas of 0% and areas of 1-4% of normal flow. RESULTS: The CTP software detected hypoperfusion down to 2-3% in CBF and 2% in CBV, while the MRP software detected that of 1-3% in CBF and 1-4% in CBV, although the lower limits varied among software packages. CONCLUSION: CTP and MRP can detect the difference between profound hypoperfusion of <5% from that of 0% in digital phantoms, suggesting their potential efficacy for assessing brain death.
  • Hideo Shichinohe, Satoshi Kuroda, Kohsuke Kudo, Masaki Ito, Masahito Kawabori, Michiyuki Miyamoto, Mitsuhiro Nakanishi, Satoshi Terae, Kiyohiro Houkin
    Translational stroke research 3 (1) 99 - 106 1868-4483 2012/03 [Refereed][Not invited]
     
    Recent studies have elucidated that transplantation of the bone marrow stromal cells (BMSC) has therapeutic potential for the central nervous system (CNS) disorders. However, no imaging modalities have been established to track the engrafted cells in the CNS in clinical situation. This study aimed to investigate the ability of magnetic resonance imaging (MRI) to visualize the BMSC labeled with superparamagnetic iron oxide (SPIO). The BMSC of mice were labeled with SPIO. Various numbers of the cells were injected into the agar phantom and were visualized using a 3.0-T MR apparatus. The SPIO-labeled cells were injected into the temperature-sensitive gelation polymer (TGP) hydrogel and were cultured for 7 days. They were also visualized just after the injection and at 7 days postinjection. After a 7-day culture, they were stained with Turnbull blue technique. T2-, T2*-, and susceptibility-weighted imaging could identify minimally 1,000 cells in the agar or TGP hydrogel, although it was difficult to quantify their number on MRI. All of these sequences could track the SPIO-labeled BMSC for at least 7 days when injected into the TGP. Turnbull blue staining revealed the survival and proliferation of the SPIO-labeled BMSC in the TGP for 7 days. The findings strongly suggest that the SPIO labeling may enable to track minimally 1,000 cells engrafted in the CNS on clinical MR apparatus. These data would be valuable to consider the application of imaging technique into cell transplantation therapy for CNS disorders.
  • Atsushi Kamei, Makoto Sasaki, Manami Akasaka, Nami Soga, Kohsuke Kudo, Shoichi Chida
    The Journal of pediatrics 160 (2) 342 - 4 0022-3476 2012/02 [Refereed][Not invited]
     
    Two preterm infants with athetoid cerebral palsy due to bilirubin encephalopathy were examined by magnetic resonance spectroscopic imaging at age 3 years. An increased glutamate/glutamine complex/creatine ratio was found in the basal ganglia. Chemical metabolic abnormalities of the basal ganglia were clearly demonstrated by color-coded metabolite images.
  • Takamasa Nanba, Kuniaki Ogasawara, Hideaki Nishimoto, Shunrou Fujiwara, Hiroki Kuroda, Makoto Sasaki, Kohsuke Kudo, Taro Suzuki, Masakazu Kobayashi, Kenji Yoshida, Akira Ogawa
    Cerebrovascular diseases (Basel, Switzerland) 34 (5-6) 358 - 67 1015-9770 2012 [Refereed][Not invited]
     
    BACKGROUND: Cerebral hyperperfusion after carotid endarterectomy (CEA), even when asymptomatic, often impairs cognitive function. However, conventional magnetic resonance (MR) imaging rarely demonstrates structural brain damage associated with postoperative cognitive impairment. MR diffusion tensor imaging (DTI) is potentially more sensitive for detection of white matter damage. Among the common parameters derived by DTI, fractional anisotropy (FA) is a marker of tract integrity, and mechanical disruption of axonal cylinders and loss of continuity of myelin sheaths may be responsible for reduced FA in white matter. The purpose of the present study was to determine whether postoperative cerebral white matter damage that can be detected by FA derived by DTI is associated with cerebral hyperperfusion after CEA and correlates with postoperative cognitive impairment. METHODS: In 70 patients undergoing CEA for ipsilateral internal carotid artery stenosis (≥70%), cerebral blood flow (CBF) was measured using single-photon emission computed tomography (SPECT) before and immediately after CEA and on postoperative day 3. FA values in cerebral white matter were assessed using DTI before and 1 month after surgery. These values were normalized and analyzed using statistical parametric mapping 5. In each corresponding voxel in the pre- and postoperative normalized FA maps of each patient, a postoperative FA value minus a preoperative FA value was calculated, and a voxel with postoperatively reduced FA was defined based on data obtained from healthy volunteers. The number of voxels with postoperatively reduced FA was calculated and defined as the volume with postoperatively reduced FA. Neuropsychological testing, consisting of the Wechsler Adult Intelligence Scale Revised, the Wechsler Memory Scale and the Rey-Osterreith Complex Figure test, was also performed preoperatively and after the first postoperative month. Postoperative cognitive impairment on neuropsychological testing in each patient was defined based on data obtained from patients with asymptomatic unruptured cerebral aneurysms. RESULTS: Post-CEA hyperperfusion on brain perfusion SPECT (CBF increase ≥100% compared with preoperative values) and postoperative cognitive impairment on neuropsychological testing were observed in 11 (16%) and 9 patients (13%), respectively. The volume with postoperatively reduced FA in cerebral white matter ipsilateral to surgery was significantly greater in patients with post-CEA hyperperfusion than in those without (p < 0.0001). This volume in cerebral white matter ipsilateral to surgery was also significantly associated with postoperative cognitive impairment (95% confidence interval, 1.559-8.853; p = 0.0085). CONCLUSIONS: Cerebral hyperperfusion after CEA results in postoperative cerebral white matter damage that correlates with postoperative cognitive impairment.
  • Yuri Zaitsu, Kohsuke Kudo, Satoshi Terae, Rie Yazu, Kinya Ishizaka, Noriyuki Fujima, Khin K Tha, E Mark Haacke, Makoto Sasaki, Hiroki Shirato
    Radiology 261 (3) 930 - 6 0033-8419 2011/12 [Refereed][Not invited]
     
    PURPOSE: To develop a map to detect changes in oxygen extraction fraction (OEF) utilizing susceptibility-weighted (SW) phase images and to correlate such changes in OEF with those in cerebral blood flow (CBF). MATERIALS AND METHODS: The study protocol was approved by the institutional review board, and written informed consent was obtained from all subjects. Eight healthy volunteers (mean age ± standard deviation, 29.8 years ± 4.6) were included in the study. Subjects were evaluated by using SW imaging, and the change in OEF was calculated by subtracting the image at baseline from one of the images obtained during six different conditions, including two at resting state, three different types of respiratory challenges, and one drug challenge with acetazolamide. Arterial spin labeling was carried out to measure CBF, while SW imaging was used to generate maps of change in OEF in response to a given condition. Statistical tests included one-way analysis of variance and Dunnett multiple comparisons to compare among the six conditions the magnitude of change from baseline for both OEF and CBF, by using the OEF change at resting state (resting 1) as the control. RESULTS: Hyperventilation caused a statistically significant decrease in CBF (-29.3%, P < .001) and an increase in OEF (+5.2%, P < .001) compared with the control, resting 1 (+2.2%, -0.7%, respectively). Acetazolamide caused a significant increase in CBF (+39.7%, P < .001) and a decrease in OEF (-3.4%, P = .040). Carbogen also induced a CBF increase (+16.2%); however, the change was not significant (P = .090), even though OEF decreased significantly (-4.2%, P = .003). Oxygen administration resulted in a significant CBF decrease (-27.2%, P < .001), whereas OEF showed no significant difference (-0.6%, P > .99). CONCLUSION: Maps of changes in OEF generated from SW phase images revealed changes in OEF corresponding to anticipated changes in CBF induced by various conditions; SW phase imaging might, in the future, be applied to evaluate cerebrovascular and other cerebral disorders in which changes in oxygen metabolism are important for planning therapeutic strategies.
  • Diffusion tensor imaging-voxel-based analysisを用いた一酸化炭素中毒亜急性期白質障害部位の特定
    藤原 俊朗, 別府 高明, 西本 英明, 村上 寿之, 三條 克己, 工藤 薫, 森 潔, 工藤 與亮, 佐々木 真理, 小川 彰, 小笠原 邦昭
    脳循環代謝 日本脳循環代謝学会 23 (1) 163 - 163 0915-9401 2011/11 [Not refereed][Not invited]
  • Noriko Oyama-Manabe, Naoki Ishimori, Hiroyuki Sugimori, Marc Van Cauteren, Kohsuke Kudo, Osamu Manabe, Tomoyuki Okuaki, Tamotsu Kamishima, Yoichi M Ito, Hiroyuki Tsutsui, Khin Khin Tha, Satoshi Terae, Hiroki Shirato
    European radiology 21 (11) 2362 - 8 0938-7994 2011/11 [Refereed][Not invited]
     
    OBJECTIVES: To investigate whether subendocardial and transmural myocardial infarction can be identified and differentiated using the peak circumferential and longitudinal strains measured by fast strain-encoded (SENC). METHODS: Nineteen patients with ischemic heart diseases underwent imaging with fast SENC and late gadolinium enhancement (LGE) MRI at 3 T. Fast SENC measurements were performed in three short-axis slices (basal, mid-ventricular and apical levels) and one long-axis view (four-chamber) to assess peak longitudinal and circumferential systolic strains. RESULTS: All patients showed myocardial infarction with an average of 7 positive LGE segments. A total of 304 segments for longitudinal strains (LS) and 114 segments for circumferential strains (CS) could be analysed. Positive LGE segments showed lower peak CS and LS compared with the no LGE segments (P < 0.0001 for both). Segments with subendocardial infarction showed reduced CS and LS compared with the no LGE segments (P < 0.0001 for both). There was a significant difference in CS between subendocardial and transmural infarct segments (P = 0.03), but no significant difference in LS between them (P = 0.64). CONCLUSIONS: Fast SENC can identify old myocardial infarction and differentiate subendocardial from transmural infarction.
  • Takaaki Beppu, Makoto Sasaki, Kohsuke Kudo, Akira Kurose, Masaru Takeda, Hiroshi Kashimura, Akira Ogawa, Kuniaki Ogasawara
    Journal of neuro-oncology 103 (3) 619 - 27 0167-594X 2011/07 [Refereed][Not invited]
     
    Tumor grade differentiation is often difficult using routine neuroimaging alone. Computed tomography perfusion imaging (CTP) provides quantitative information on tumor vasculature that closely parallels the degree of tumor malignancy. This study examined whether CTP is useful for preoperatively predicting the grade of malignancy in glioma showing no enhancement on contrast-enhanced magnetic resonance imaging (MRI). Subjects comprised 17 patients with supratentorial glioma without enhancement on MRI. CTP was performed preoperatively, and absolute values and normalized ratios of parameters were calculated. Postoperatively, subjects were classified into two groups according to histological diagnosis of grade 3 (G3) glioma or grade 2 (G2) glioma. Absolute values and normalized ratios for each parameter were compared between G3 and G2. Accuracies of normalized ratios for cerebral blood flow (nCBF) and cerebral blood volume (nCBV) in predicting a diagnosis of G3 were assessed. In addition, nCBV was compared between diffuse astrocytoma, G2 oligodendroglial tumor (OT), and G3 OT. Values for nCBF and nCBV differed significantly between G3 and G2. Using nCBV of 1.6 as a cutoff, specificity and sensitivity for distinguishing G3 were 83.3% and 90.9%, respectively. No significant difference in nCBV was seen between diffuse astrocytoma and G2 OT, whereas differences were noted between G2 and G3 OTs, and between diffuse astrocytoma and G3 OT. CTP offers a useful method for differentiating between G3 and G2 in nonenhancing gliomas.
  • Shunrou Fujiwara, Makoto Sasaki, Tsukasa Wada, Kohsuke Kudo, Ryonoshin Hirooka, Daiya Ishigaki, Yasumasa Nishikawa, Ayumi Ono, Mao Yamaguchi, Kuniaki Ogasawara
    Journal of neuroimaging : official journal of the American Society of Neuroimaging 21 (2) e102-8 - e108 1051-2284 2011/04 [Refereed][Not invited]
     
    PURPOSE: To detect diffusion abnormalities in the trigeminal nerves of patients with trigeminal neuralgia (TN) caused by neurovascular compression (NVC) by using a high-resolution diffusion tensor imaging (HR-DTI) technique. METHODS: Thirteen patients with TN and 14 healthy controls underwent HR-DTI scanning. After extracting the trigeminal nerve using a tractography technique, we measured the fractional anisotropy (FA) and apparent diffusion coefficient (ADC), and compared the contralateral ratios (CR) of these parameters between the patients and controls, and correlated these ratios with the cross-sectional areas of the nerves. RESULTS: The CRs of the FA values for the trigeminal nerves of the patients (1.00±0.15) had significantly higher variance than those of healthy controls (1.00±0.05) (P<.05) and showed a positive correlation with the cross-sectional area of the nerves (r=0.81). In contrast, the CRs of the ADC values were not significantly different between the two groups (1.02±0.10 and 1.01±0.08, respectively) and had no significant correlation with cross-sectional area. CONCLUSION: HR-DTI can detect an alteration in the relative FA values of affected trigeminal nerves and a correlation with atrophic changes in patients with NVC-induced TN.
  • Kohsuke Kudo, Makoto Sasaki, Leif Østergaard, Soren Christensen, Ikuko Uwano, Masako Suzuki, Kuniaki Ogasawara, Hiroki Shirato, Akira Ogawa
    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 31 (3) 908 - 12 0271-678X 2011/03 [Refereed][Not invited]
     
    The time-to-maximum of the tissue residue function (T(max)) perfusion index has proven very predictive of infarct growth in large clinical trials, yet its dependency on simple tracer delays remains unknown. Here, we determine the dependency of computed tomography (CT) perfusion (CTP) T(max) estimates on tracer delay using a range of deconvolution techniques and digital phantoms. Digital phantom data sets simulating the tracer delay were created from CTP data of six healthy individuals, in which time frames of the left cerebral hemisphere were shifted forward and backward by up to ±5 seconds. These phantoms were postprocessed with three common singular value decomposition (SVD) deconvolution algorithms-standard SVD (sSVD), block-circulant SVD (bSVD), and delay-corrected SVD (dSVD)-with an arterial input function (AIF) obtained from the right middle cerebral artery (MCA). The T(max) values of the left hemisphere were compared among different tracer delays and algorithms by a region of interest-based analysis. The T(max) values by sSVD were positively correlated with 'positive shifts' but unchanged with 'negative shifts,' those by bSVD had an excellent positive linear correlation with both positive and negative shifts, and those by dSVD were relatively constant, although slightly increased with the positive shifts. The T(max) is a parameter highly dependent on tracer delays and deconvolution algorithm.
  • Makoto Sasaki, Kohsuke Kudo, Kaneyoshi Honjo, Jin-Qing Hu, Hai-Bin Wang, Katsuya Shintaku
    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 31 (2) 448 - 56 0271-678X 2011/02 [Refereed][Not invited]
     
    By optimizing thresholds, we identified the perfusion-weighted magnetic resonance imaging (PWI) parameters that accurately predict final infarct volume and neurologic outcome in a primate model of permanent middle cerebral artery (MCA) occlusion. Ten cynomolgus monkeys underwent PWI and diffusion-weighted imaging (DWI) at 3 and 47 hours, respectively, after right MCA occlusion using platinum coils, and were killed at 48 hours. Volumes of the hypoperfused areas on PWI were automatically measured using different thresholds and 11 parametric maps to determine the optimum threshold (at which least difference was found between the average volumes on PWI and those determined using specimens or DWI). In the case of arrival time (AT), cerebral blood volume (CBV), time to peak (TTP), time to maximum (T(max)), and cerebral blood flow (CBF) determined using deconvolution techniques, the volume of the hypoperfused area significantly correlated with the infarct volumes and the neurologic deficit scores with small variations, whereas in the case of mean transit time and nondeconvolution CBF, relatively poor correlations with large variations were seen. At optimum threshold, AT, CBV, TTP, T(max), and deconvolution CBF can accurately predict the final infarct volume and neurologic outcome in monkeys with permanent MCA occlusion.
  • Noriyuki Fujima, Kohsuke Kudo, Satoshi Terae, Kinya Ishizaka, Rie Yazu, Yuri Zaitsu, Khin Khin Tha, Daisuke Yoshida, Akiko Tsukahara, Mark E Haacke, Makoto Sasaki, Hiroki Shirato
    NeuroImage 54 (1) 344 - 9 1053-8119 2011/01/01 [Refereed][Not invited]
     
    Susceptibility-weighted imaging (SWI) has been used for quantitative and non-invasive measurement of blood oxygen saturation in the brain. In this study, we used SWI for quantitative measurement of oxygen saturation in the spinal vein to look for physiological- or caffeine-induced changes in venous oxygenation. SWI measurements were obtained for 5 healthy volunteers using 1.5-T MR units, under 1) 3 kinds of physiological load (breath holding, Bh; hyperventilation, Hv; and inspiration of highly concentrated oxygen, Ox) and 2) caffeine load. Oxygen saturation in the anterior spinal vein (ASV) was calculated. We evaluated changes in oxygen saturation induced by physiological load. We also evaluated the time-course of oxygen saturation after caffeine intake. For the physiological load measurements, the average oxygen saturation for the 5 subjects was significantly lower in Hv (0.75) and significantly higher in Bh (0.84) when compared with control (0.80). There was no significant difference between Ox (0.81) and control. Oxygen saturation gradually decreased after caffeine intake. The average values of oxygen saturation were 0.79 (0 min), 0.76 (20 min), 0.74 (40 min), and 0.73 (60 min), respectively. We demonstrated a significant difference in oxygen saturation at 40 and 60 min after caffeine intake when compared with 0 min. In conclusion, we demonstrated the feasibility of using SWI for non-invasive measurement of oxygen saturation in the spinal vein. We showed changes in oxygen saturation under physiological as well as caffeine load and suggest that this method is a useful tool for the clinical evaluation of spinal cord oxygenation.
  • Yusuke Shimoda, Kohsuke Kudo, Satoshi Kuroda, Yuri Zaitsu, Nobuyuki Fujima, Satoshi Terae, Makoto Sasaki, Kiyohiro Houkin
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 10 (1) 49 - 52 1347-3182 2011 [Refereed][Not invited]
     
    We performed magnetic resonance angiography (MRA) and susceptibility-weighted imaging (SWI) to observe cerebral changes during a migraine attack in a 28-year-old man. MRA revealed regional arterial spasm, and findings of SWI were consistent with decreased blood flow and/or venous dilatation. Because these noninvasive techniques can be performed repeatedly at short intervals, they can be useful for evaluating hemodynamic changes during and after migraine attacks.
  • Masako Suzuki, Kohsuke Kudo, Makoto Sasaki, Satoshi Takahashi, Jyunko Takahashi, Noriyuki Fujima, Ikuko Uwano, Hisashi Yonezawa, Masako Kudo, Hikoaki Fukaura, Naoki Ishizuka, Yasuo Terayama
    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 10 (3) 185 - 92 1347-3182 2011 [Refereed][Not invited]
     
    PURPOSE: Susceptibility-weighted (SW) imaging is a magnetic resonance (MR) imaging technique reported effective in visualizing multiple sclerosis (MS) plaques, but its capacity to distinguish active plaques remains unclear. We evaluated active plaque detection by SW compared with contrast-enhanced MR imaging. METHODS: We prospectively examined 11 patients using a 3-tesla scanner. Two neuroradiologists independently evaluated signal changes of plaques and accompanying low signal rims in 74 plaques on various SW images (magnitude, phase, and minimum intensity projection [minIP]), and on contrast-enhanced T(1)-weighted images (T(1)WI). We correlated signal alterations on various SW images and contrast enhancement on T(1)WI using Fisher's exact test and calculated sensitivity and specificity for predicting gadolinium enhancement. RESULTS: Only changes in plaque signal on SW magnitude images correlated significantly with contrast enhancement of the plaques (P=0.008), and high signal intensity had 0.556 sensitivity and 0.787 specificity for predicting contrast-enhanced plaques. Furthermore, plaques with rims of low signal showed sensitivity of 0.296 and specificity of 0.957. CONCLUSIONS: Susceptibility-weighted magnitude, but not phase or minIP, images can predict MS plaques with contrast enhancement with high specificity.
  • 高解像度磁気共鳴画像を用いた穿通枝領域梗塞における中大脳動脈・脳底動脈の動脈硬化性プラークの検出 磁気共鳴血管造影との比較(Detection of atherosclerotic plaques in middle cerebral and basilar arteries in large infarctions of perforating artery territories using high-resolution magnetic resonance plaque imaging at 3T: comparison with magnetic resonance angiography)
    桂 永行, 佐々木 真理, 石橋 靖宏, 米澤 久司, 工藤 雅子, 工藤 與亮, 高橋 純子, 高橋 智, 寺山 靖夫
    岩手医学雑誌 62 (5) 353 - 362 0021-3284 2010/12 [Refereed][Not invited]
     
    穿通枝領域のアテローム血栓性脳梗塞は、頭蓋内動脈の狭窄を伴わない場合,診断に苦慮することがある.そこで,穿通枝脳梗塞における高解像度MRIの頭蓋内動脈プラーク検出能をMRAの狭窄病変検出能と比較した.基底核・橋穿通枝領域のアテローム血栓性脳梗塞疑い患者18名に高解像度MRIとMRAを撮像し,中大脳動脈水平部(M1),脳底動脈のプラーク・狭窄の有無を視覚的に判定した.高解像度MRIにおけるプラーク検出率は72〜83%で,MRAにおける狭窄性変化(50%,うち高度狭窄17%)に比し高率であった.脳底動脈では高解像度MRIのプラーク検出率は89〜100%で,MRAの44%に比し有意に高かったが,M1では56〜66%で,MRAと同程度であった.高解像度MRIはMRAで頭蓋内動脈狭窄を認めない例でもプラークを検出することができ,穿通枝領域脳梗塞の病型診断に有用と考えられる.(著者抄録)
  • Toshiyuki Murakami, Kuniaki Ogasawara, Yoshichika Yoshioka, Daiya Ishigaki, Makoto Sasaki, Kohsuke Kudo, Kenta Aso, Hideaki Nishimoto, Masakazu Kobayashi, Kenji Yoshida, Akira Ogawa
    Radiology 256 (3) 924 - 31 0033-8419 2010/09 [Refereed][Not invited]
     
    PURPOSE: To determine whether brain temperature measured by using preoperative proton magnetic resonance (MR) spectroscopy could help identify patients at risk for cerebral hyperperfusion after carotid endarterectomy (CEA). MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. Acquisition of proton MR spectroscopic data by using point-resolved spectroscopy without water suppression was performed before CEA in the bilateral cerebral hemispheres of 84 patients with unilateral internal carotid artery stenosis (> or =70%) and without contralateral internal carotid artery steno-occlusive disease. Brain temperature was calculated from the chemical shift difference between water and N-acetylaspartate signals at proton MR spectroscopy. Cerebral blood flow (CBF) was also measured by using single photon emission computed tomography and N-isopropyl-p-[(123)I]-iodoamphetamine before and immediately after CEA and on the 3rd postoperative day. The relationship between each variable and the development of post-CEA hyperperfusion (CBF increase > or = 100% compared with preoperative values) was evaluated with univariate statistical analysis followed by multivariate analysis. RESULTS: A linear correlation was observed between preoperative brain temperature difference (the value in the affected hemisphere minus the value in the contralateral hemisphere) and increases in CBF immediately after CEA (r = 0.763 and P < .001) when the preoperative brain temperature difference was greater than 0. Cerebral hyperperfusion immediately after CEA was observed in nine patients (11%). Elevated preoperative brain temperature difference was the only significant independent predictor of post-CEA hyperperfusion. When elevated brain temperature difference was defined as a marker of hemodynamic impairment in the affected cerebral hemisphere, use of preoperative brain temperature difference resulted in 100% sensitivity and 87% specificity, with a 47% positive predictive value and a 100% negative predictive value for the prediction of post-CEA hyperperfusion. Hyperperfusion syndrome developed on the 3rd and 4th postoperative days in two of the nine patients who exhibited hyperperfusion immediately after CEA. CONCLUSION: Brain temperature measured by using preoperative proton MR spectroscopy may help identify patients at risk for post-CEA cerebral hyperperfusion.
  • Fumio Yamashita, Makoto Sasaki, Satoshi Takahashi, Hiroshi Matsuda, Kohsuke Kudo, Shinsuke Narumi, Yasuo Terayama, Takashi Asada
    NEURORADIOLOGY 52 (5) 381 - 386 0028-3940 2010/05 [Refereed][Not invited]
     
    We attempted to detect alterations in the cerebrospinal fluid (CSF) space in patients with idiopathic normal pressure hydrocephalus (iNPH) using voxel-based morphometry (VBM). We obtained sagittal volume images of the entire head by three-dimensional T1-weighted magnetic resonance imaging and compared the regional distribution of CSF in 12 patients with iNPH, 14 patients with Alzheimer's disease (AD), and 17 healthy individuals using VBM with automatically extracted CSF objects. VBM demonstrated significant widening at the lateral ventricles and Sylvian fissures and narrowing of the CSF space at the high convexity/midline areas in iNPH patients, compared to the AD patients and healthy controls (p < 0.05, after correction with a false-discovery rate). In addition, the ratio of the CSF volume in the lateral ventricle/Sylvian fissure area to that in the high convexity/midline area in iNPH patients (3.9 +/- 1.2) was remarkably greater than that in AD patients (1.2 +/- 0.3) and controls (0.9 +/- 0.3; one-way ANOVA, p < 0.001; post hoc Tukey's test, p < 0.001); we could discriminate iNPH patients from those in the other two groups without any overlap, when using a cutoff level of 1.9. VBM using CSF objects can be used to delineate the characteristic alteration of the CSF space in iNPH patients, which has been evaluated by visual interpretation.
  • Khin K Tha, Satoshi Terae, Ichiro Yabe, Tamaki Miyamoto, Hiroyuki Soma, Yuri Zaitsu, Noriyuki Fujima, Kohsuke Kudo, Hidenao Sasaki, Hiroki Shirato
    Radiology 255 (2) 563 - 9 0033-8419 2010/05 [Refereed][Not invited]
     
    PURPOSE: To determine whether diffusion-tensor (DT) imaging can demonstrate microstructural white matter abnormalities of multiple system atrophy (MSA) and to correlate these imaging findings with clinical signs and symptoms. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained. DT imaging was performed in 16 patients with MSA with predominant cerebellar symptoms (MSA-C) (mean age, 60.0 years + or - 5.1 [standard deviation]; range, 51-69 years) and 16 age-matched healthy subjects. Fractional anisotropy (FA) and mean diffusivity (MD) were compared voxel-by-voxel between the two groups by using a two-sample t test. Overlap maps were created to illustrate areas with FA and MD alterations. Correlation between DT imaging indexes and Barthel index score, scale for assessment and rating of ataxia (SARA) score, severity of orthostatic hypotension, age of disease onset, and disease duration was tested by using Spearman rank or Pearson product-moment correlation analysis. T2-weighted and proton density-weighted images of the patients were visually assessed. RESULTS: Widespread areas of FA reduction and MD elevation were observed in supra- and infratentorial white matter structures in patients with MSA (P < .05, false discovery rate corrected). Significant correlation (P < .01) between DT imaging indexes and Barthel index score, SARA score, severity of orthostatic hypotension, and disease duration was observed for multiple areas with FA and/or MD alterations. T2-weighted and proton density-weighted images showed no significant abnormality in supratentorial white matter. CONCLUSION: DT imaging may help identify the microstructural white matter abnormalities of MSA-C. DT imaging may be useful for severity assessment of MSA-C.
  • Noriyuki Fujima, Kohsuke Kudo, Satoshi Terae, Kazutoshi Hida, Kinya Ishizaka, Yuri Zaitsu, Takeshi Asano, Daisuke Yoshida, Khin Khin Tha, E Mark Haacke, Makoto Sasaki, Hiroki Shirato
    Radiology 254 (3) 891 - 9 0033-8419 2010/03 [Refereed][Not invited]
     
    PURPOSE: To evaluate the efficacy of susceptibility-weighted (SW) magnetic resonance (MR) imaging for the assessment of the posttreatment change in oxygen saturation in the draining vein in patients with spinal arteriovenous malformation (AVM). MATERIALS AND METHODS: The study protocol was approved by the institutional review board, and written informed consent was obtained from all subjects. SW imaging was performed in 11 patients with spinal AVM before and after surgical or endovascular treatment. Eleven healthy subjects were included as a control group. A four-grade response scale was used for the visual assessment of the anterior spinal vein (ASV). For quantitative analysis, the phase value of the ASV was measured and oxygen saturation was calculated. Nonparametric multigroup comparison for visual assessment and one-way analysis of variance for quantitative measurement of oxygen saturation were used as statistical tests for comparison among three groups (pretreatment patients, posttreatment patients, and control subjects). RESULTS: Complete shunt occlusion in all patients was confirmed by using conventional angiography. For visual assessment, the average score of the pretreatment group was significantly less than that of the posttreatment and control groups. For quantitative analysis, the average oxygen saturation of the pretreatment group was significantly higher than that of the posttreatment and control groups, while no significant difference was observed between the posttreatment and control groups. CONCLUSION: After treatment, normalization of increased oxygen saturation was noninvasively observed by using SW imaging in patients with spinal AVM. SW imaging can be a useful tool for the assessment of treatment efficacy in patients with spinal AVM. (c) RSNA, 2010.
  • Makoto Sasaki, Eri Shibata, Kotaro Ohtsuka, Jin Endoh, Kohsuke Kudo, Shinsuke Narumi, Akio Sakai
    NEURORADIOLOGY 52 (2) 83 - 89 0028-3940 2010/02 [Refereed][Not invited]
     
    Fast spin-echo (FSE) T1-weighted (T1W) magnetic resonance imaging (MRI) at 3T, which is sensitive to neuromelanin-related contrast, can quantitatively detect signal alterations in the locus ceruleus (LC) and the substantia nigra pars compacta (SNc) of depressive and schizophrenic patients; however, its qualitative diagnostic performance remains unknown. We investigated whether visual interpretation of semiquantitative color maps can be used for discriminating between depressive and schizophrenic patients and healthy individuals. We retrospectively examined 23 patients with major depression, 23 patients with schizophrenia, and 23 age-matched healthy controls by using a FSE-T1W MRI technique. Semiquantitative color maps of sections through the LC and SNc were visually interpreted by nine raters using a continuous confidence rating scale for receiver operating characteristic (ROC) analysis. The area under the ROC curve (Az), which reflects the performance in differentiating between depressive patients and controls, was 0.88, and the sensitivity and specificity at the maximum likelihood were 76% and 83%, respectively. In contrast, the Az value, sensitivity, and specificity values between schizophrenics and controls and between depressives and schizophrenics were 0.66 and 0.69, 42% and 48%, and 82% and 84%, respectively. Semiquantitative, color-coded FSE-T1W MRI at 3T can be used for visually differentiating depressive patients from healthy individuals with a substantially high likelihood, but this technique cannot be applied to distinguish schizophrenic patients from the other two groups.
  • Kohsuke Kudo, Makoto Sasaki, Kei Yamada, Suketaka Momoshima, Hidetsuna Utsunomiya, Hiroki Shirato, Kuniaki Ogasawara
    Radiology 254 (1) 200 - 9 2010/01 [Refereed][Not invited]
     
    PURPOSE: To examine the variability in the qualitative and quantitative results of computed tomographic (CT) perfusion imaging generated from identical source data of stroke patients by using commercially available software programs provided by various CT manufacturers. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. CT perfusion imaging data of 10 stroke patients were postprocessed by using five commercial software packages, each of which had a different algorithm: singular-value decomposition (SVD), maximum slope (MS), inverse filter (IF), box modulation transfer function (bMTF), and by using custom-made original software with standard (sSVD) and block-circulant (bSVD) SVD methods. Areas showing abnormalities in cerebral blood flow (CBF), mean transit time (MTT), and cerebral blood volume (CBV) were compared with each other and with the final infarct areas. Differences among the ratios of quantitative values in the final infarct areas and those in the unaffected side were also examined. RESULTS: The areas with CBF or MTT abnormalities and the ratios of these values significantly varied among software, while those of CBV were stable. The areas with CBF or MTT abnormalities analyzed by using SVD or bMTF corresponded to those obtained with delay-sensitive sSVD, but overestimated the final infarct area. The values obtained from software by using MS or IF corresponded well with those obtained from the delay-insensitive bSVD and the final infarct area. Given the similarities between CBF and MTT, all software were separated in two groups (ie, sSVD and bSVD). The ratios of CBF or MTTs correlated well within both groups, but not across them. CONCLUSION: CT perfusion imaging maps were significantly different among commercial software even when using identical source data, presumably because of differences in tracer-delay sensitivity.
  • Kinya Ishizaka, Kohsuke Kudo, Noriyuki Fujima, Yuri Zaitsu, Rie Yazu, Khin Khin Tha, Satoshi Terae, E Mark Haacke, Makoto Sasaki, Hiroki Shirato
    Journal of magnetic resonance imaging : JMRI 31 (1) 32 - 8 1053-1807 2010/01 [Refereed][Not invited]
     
    PURPOSE: To evaluate the visualization of the spinal veins using susceptibility-weighted imaging (SWI). MATERIALS AND METHODS: A 1.5-T magnet equipped with a spine matrix coil was used. Axial SWI scans of 20 healthy volunteers were obtained with a three-dimensional fast low-angle shot (3D-FLASH) sequence. Maximum intensity projection (MIP) of the phase images were reconstructed and five MIP images (at the levels of T11, T11/12, T12, T12/L1, and L1) were selected for the evaluation. The anterior median vein (AMV), posterior median vein (PMV), anterior radiculomedullary vein (ARV), posterior radiculomedullary vein (PRV), and sulcal vein (SV) were evaluated using a 4-grade scale (0, none; 1, weak; 2, moderate; and 3, prominent). RESULTS: The AMV was detected in all the subjects (100%). The detection rates of the other veins were lower: PMV, 65%; right ARV, 45%; left ARV, 15%; right PRV, 10%; left PRV, 30%; and SV, 0%. The average scores for AMV, PMV, right ARV, left ARV, right PRV, left PRV, and SV were 0.98, 0.24, 0.20, 0.08, 0.08, 0.14, and 0, respectively. CONCLUSION: SWI of the spine is feasible. The extrinsic spinal veins can be visualized by SWI without using contrast materials.
  • Yuri Zaitsu, Satoshi Terae, Kohsuke Kudo, Khin Khin Tha, Mineji Hayakawa, Noriyuki Fujima, Daisuke Yoshida, Akiko Tsukahara, Hiroki Shirato
    Journal of computer assisted tomography 34 (1) 107 - 12 0363-8715 2010/01 [Refereed][Not invited]
     
    Cerebral fat embolism (CFE) causes microinfarcts, vasogenic edema, and petechiae in the brain. Conventional magnetic resonance imaging has been reported to effectively visualize microinfarcts and vasogenic edema in CFE, but not petechiae. We report 3 cases of CFE in which susceptibility-weighted imaging distinctly demonstrated multiple minute hypointense foci in the brain, which were interpreted as petechiae, susceptibility-weighted imaging is a useful adjunct to conventional magnetic resonance imaging for the evaluation of CFE.
  • Benjamin Hotter, Sandra Pittl, Martin Ebinger, Gabriele Oepen, Kati Jegzentis, Kohsuke Kudo, Michal Rozanski, Wolf U. Schmidt, Peter Brunecker, Chao Xu, Peter Martus, Matthias Endres, Gerhard J. Jungehuelsing, Arno Villringer, Jochen B. Fiebach
    BMC NEUROLOGY 9 60  1471-2377 2009/12 [Refereed][Not invited]
     
    Background: The mismatch between diffusion weighted imaging (DWI) lesion and perfusion imaging (PI) deficit volumes has been used as a surrogate of ischemic penumbra. This pathophysiology-orientated patient selection criterion for acute stroke treatment may have the potential to replace a fixed time window. Two recent trials - DEFUSE and EPITHET - investigated the mismatch concept in a multicenter prospective approach. Both studies randomized highly selected patients (n = 74/n = 100) and therefore confirmation in a large consecutive cohort is desirable. We here present a single-center approach with a 3T MR tomograph next door to the stroke unit, serving as a bridge from the ER to the stroke unit to screen all TIA and stroke patients. Our primary hypothesis is that the prognostic value of the mismatch concept is depending on the vessel status. Primary endpoint of the study is infarct growth determined by imaging, secondary endpoints are neurological deficit on day 5-7 and functional outcome after 3 months. Methods and design: 1000Plus is a prospective, single centre observational study with 1200 patients to be recruited. All patients admitted to the ER with the clinical diagnosis of an acute cerebrovascular event within 24 hours after symptom onset are screened. Examinations are performed on day 1, 2 and 5-7 with neurological examination including National Institute of Health Stroke Scale (NIHSS) scoring and stroke MRI including T2*, DWI, TOF-MRA, FLAIR and PI. PI is conducted as dynamic susceptibility-enhanced contrast imaging with a fixed dosage of 5 ml 1 M Gadobutrol. For post-processing of PI, mean transit time (MTT) parametric images are determined by deconvolution of the arterial input function (AIF) which is automatically identified. Lesion volumes and mismatch are measured and calculated by using the perfusion mismatch analyzer (PMA) software from ASIST-Japan. Primary endpoint is the change of infarct size between baseline examination and day 5-7 follow up. Discussions: The aim of this study is to describe the incidence of mismatch and the predictive value of PI for final lesion size and functional outcome depending on delay of imaging and vascular recanalization. It is crucial to standardize PI for future randomized clinical trials as for individual therapeutic decisions and we expect to contribute to this challenging task.
  • K K Tha, S Terae, K Kudo, K Miyasaka
    The British journal of radiology 82 (979) 610 - 4 0007-1285 2009/07 [Refereed][Not invited]
     
    The fluid-attenuated inversion recovery imaging sequence is a widely used MRI sequence of the brain. It is an inversion recovery pulse sequence, designed to suppress signals from the cerebrospinal fluid. It is highly sensitive for detection of lesions adjacent to or within the cerebrospinal fluid, associated with T(2) prolongation or T(1) shortening. The term "hyperintense cerebrospinal fluid" is used to describe failed suppression or hyperintensity of cerebrospinal fluid on fluid-attenuated inversion recovery imaging of the brain. It is often encountered in many important pathological conditions, including subarachnoid haemorrhage, meningitis and leptomeningeal metastasis. However, certain non-pathological states in which there is no definite cerebrospinal fluid abnormality can also present with hyperintense cerebrospinal fluid. Correct interpretation of abnormalities is important to arrive at an appropriate diagnosis. This pictorial review provides fluid-attenuated inversion recovery images of hyperintense cerebrospinal fluid of the brain and describes distinguishing features, focusing on non-pathological conditions.
  • Masahito Kawabori, Satoshi Kuroda, Kohsuke Kudo, Satoshi Terae, Makoto Kaneda, Naoki Nakayama, Yoshinobu Iwasaki
    Neurologia medico-chirurgica 49 (6) 248 - 51 0470-8105 2009/06 [Refereed][Not invited]
     
    An 11-year-old female receiving treatment for acute lymphoblastic leukemia presented with superior sagittal sinus (SSS) thrombosis. T(1)-weighted, T(2)-weighted, and fluid-attenuated inversion recovery magnetic resonance (MR) imaging, and MR venography showed that the SSS was totally occluded by thrombus. Susceptibility-weighted MR imaging showed hypointense thrombus in the SSS and markedly dilated cortical veins over the bilateral cerebral hemispheres. Two days later, her symptoms had slightly resolved. Iodine-123 N-isopropyl-p-iodoamphetamine single photon emission computed tomography showed marked decrease of cerebral blood flow in the bilateral frontal lobes, indicating that venous congestion had disturbed the cerebral hemodynamics. MR venography showed that the SSS was still mostly occluded, but susceptibility-weighted imaging showed that the dilation of the cortical veins was less marked, suggesting that collateral venous routes had gradually developed. The finding of dilated cortical veins had almost disappeared at 28 days after the onset. Susceptibility-weighted imaging can be used as a non-invasive method to monitor the severity of venous congestion caused by cerebral venous sinus thrombosis.
  • K K Tha, S Terae, K Kudo, K Miyasaka
    The British journal of radiology 82 (977) 426 - 34 0007-1285 2009/05 [Refereed][Not invited]
     
    The fluid-attenuated inversion recovery imaging sequence is a widely used MRI sequence of the brain. It is an inversion recovery pulse sequence, designed to suppress signals from the cerebrospinal fluid. It is highly sensitive in detection of lesions adjacent to or within the cerebrospinal fluid associated with T(2) prolongation or T(1) shortening. The term "hyperintense cerebrospinal fluid" is used to describe failed suppression, or hyperintensity, of cerebrospinal fluid on fluid-attenuated inversion recovery imaging of the brain. It is often encountered in many important pathological conditions, including subarachnoid haemorrhage, meningitis and leptomeningeal metastasis. However, certain non-pathological states in which there is no definite cerebrospinal fluid abnormality can also present with hyperintense cerebrospinal fluid. Correct interpretation of abnormalities is important to arrive at an appropriate diagnosis. This pictorial review provides fluid-attenuated inversion recovery images of hyperintense cerebrospinal fluid of the brain and describes distinguishing features. Part I features pathological conditions whereas Part II focuses on non-pathological conditions.
  • Kohsuke Kudo, Makoto Sasaki, Kuniaki Ogasawara, Satoshi Terae, Shigeru Ehara, Hiroki Shirato
    Radiology 251 (1) 241 - 9 0033-8419 2009/04 [Refereed][Not invited]
     
    Institutional review board approval and informed consent were obtained. The purpose was to evaluate the differences in tracer delay-induced effects of various deconvolution algorithms for computed tomographic (CT) perfusion imaging by using digital phantoms created from actual source data. Three methods of singular value decomposition (SVD) were evaluated. For standard SVD (sSVD), the delays induced significant errors in cerebral blood flow and mean transit time. In contrast, for block-circulant SVD (bSVD), these values remained virtually unchanged, whereas for delay-corrected SVD (dSVD), mild changes were observed. bSVD was superior to sSVD and dSVD for avoiding the tracer delay-induced effects in CT perfusion imaging.
  • M. Sasaki, K. Kudo, K. Ogasawara, S. Fujiwara
    AMERICAN JOURNAL OF NEURORADIOLOGY 30 (1) 188 - 193 0195-6108 2009/01 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Reliability of CT perfusion (CTP) algorithms has not been fully validated. We investigated whether the cerebral blood flow (CBF) values obtained by using a dynamic CTP technique with a tracer delay-insensitive deconvolution algorithm are more accurate than those obtained by using CTP with delay-sensitive algorithms in unilateral cerebrovascular steno-occlusive disease, when compared with those generated by quantitative single-photon emission CT (SPECT). MATERIALS AND METHODS: Using CTP and iodine-123-N-isopropyl-p-iodoamphetamine SPECT with an autoradiographic quantification technique, we examined 20 patients with suggested hemodynamic ischemia due to stenosis or occlusion of the unilateral internal carotid or middle cerebral artery. The algorithms used for CTP included delay-insensitive block-circulant singular value decomposition (SVD) (bSVD) and delay-sensitive standard SVD (sSVD) and box-modulation transfer function (bMTF). RESULTS: Absolute CBF values obtained by using CTP with bSVD were significantly lower than those obtained with SPECT, but the ratios to the nonaffected side were significantly correlated to the quantitative SPECT values with significant agreements, particularly when the arterial input function was obtained from the unaffected side. Contrastingly, CBF ratios with sSVD and bMTF were significantly underestimated, and no significant agreement was determined between CTP with sSVD or bMTF and SPECT, though there were substantial correlations between them in some parameters. CONCLUSIONS: With the CTP technique, the insensitivity of the deconvolution algorithm to the tracer-delay effect appears to be essential for estimating semiquantitative CBF values in patients with unilateral steno-occlusive lesions.
  • Makoto Sasaki, Eri Shibata, Koujiro Tohyama, Kohsuke Kudo, Jin Endoh, Kotaro Otsuka, Akio Sakai
    Neuroreport 19 (17) 1649 - 54 0959-4965 2008/11/19 [Refereed][Not invited]
     
    By using high-resolution, conventional, and neuromelanin-sensitive magnetic resonance imaging techniques, we reviewed the normal anatomy of the nuclei consisting of monoamine neurons such as dopaminergic, noradrenergic, and serotoninergic neurons and noted the changes in these nuclei that occur in some degenerative and psychiatric disorders. Multimodal MR images can directly or indirectly help in identifying the substantia nigra, locus ceruleus, and raphe nuclei that contain monoamine neurons. Neuromelanin-sensitive magnetic resonance imaging can detect signal alterations in the substantia nigra pars compacta and/or locus ceruleus that occur in Parkinson's disease and psychiatric disorders such as depression and schizophrenia. This technique seems to be promising for the noninvasive evaluation of the pathological or functional changes in the monoamine system that occur in degenerative and psychiatric disorders.
  • Sasaki Makoto, Shibata Eri, Kudo Kohsuke, Tohyama Koujiro
    CLINICAL NEURORADIOLOGY 18 (3) 147 - 153 1869-1439 2008/08 [Refereed][Not invited]
  • Jiani Hu, Yingjian Yu, Csaba Juhasz, Zhifeng Kou, Yang Xuan, Zahid Latif, Kohsuke Kudo, Harry T. Chugani, E. Mark Haacke
    JOURNAL OF MAGNETIC RESONANCE IMAGING 28 (2) 300 - 307 1053-1807 2008/08 [Refereed][Not invited]
     
    Purpose: To evaluate the efficacy of susceptibility weighted imaging (SWI) in comparison to standard Tl weighted postgadolinium contrast (T1-Gd) MRI in patients with SturgeWeber Syndrome (SWS). Materials and Methods: Twelve children (mean age, 5.6 years) with the diagnosis of SWS and unilateral hemispheric involvement were recruited prospectively and examined with high resolution three dimensional SWI and conventional TI-Gd. Both SWI and TI-Gd images were evaluated using a four-grade scoring system according to six types of imaging findings (enlargement of transmedullary veins, periventricular veins, and choroid plexus, as well as leptomeningeal abnormality, cortical gyriform abnormality, and gray matter/white matter junctional abnormality). The scores of SWI versus T1-Gd images were then compared for each type of abnormality. Results: SWI was superior to T1-Gd in identifying the enlarged transmedullary veins (P = 0.0020), abnormal periventricular veins (P = 0.0078), cortical gyriform abnormalities (P = 0.0020), and gray matter/white matter junction abnormalities (P = 0.0078). Conversely, TI-Gd was better than SWI in identifying enlarged choroid plexus (P = 0.0050) and leptomeningeal abnormalities (P = 0.0050). Conclusion: SWI can provide useful and unique information complementary to conventional contrast enhanced TI weighted MRI for characterizing SWS. Therefore, SWI should be integrated into routine clinical MRI protocols for suspected SWS.
  • Saito N, Kudo K, Sasaki T, Uesugi M, Koshino K, Miyamoto M, Suzuki S
    Radiological physics and technology 1 (1) 62 - 74 1865-0333 2008/01 [Refereed][Not invited]
  • Satoshi Terae, Daisuke Yoshida, Kohsuke Kudo, Khin Khin Tha, Masaharu Fujino, Kazuo Miyasaka
    Journal of magnetic resonance imaging : JMRI 25 (3) 479 - 87 1053-1807 2007/03 [Refereed][Not invited]
     
    PURPOSE: To assess whether the use of postcontrast fluid-attenuated inversion recovery (FLAIR) imaging in combination with pre- and postcontrast magnetization transfer (MT) T1-weighted imaging (T1WI) can increase diagnostic confidence in the evaluation of brain metastases. MATERIALS AND METHODS: Brain MR images from 41 patients with suspected brain metastases were reviewed. Two radiologists viewed pre- and postcontrast MT-T1W images for the presence of metastatic tumors and rated the possible enhanced lesions using a five-point confidence scale (session 1). The postcontrast FLAIR images were then viewed together with pre- and postcontrast MT-T1W images, and the presence of metastasis was rated again (session 2). RESULTS: A total of 240 possible enhanced lesions were detected in session 1. Judging by follow-up MR examinations, 196 were considered to be nonmetastatic findings and 44 were determined to be metastasis. In session 2 the confidence rating for nonmetastasis increased significantly in the subset of nonmetastatic findings (P < 0.001), and the confidence rating for metastasis increased significantly in the subset of metastases (P < 0.05). CONCLUSION: The addition of postcontrast FLAIR imaging to pre- and postcontrast MT-T1WI improves diagnostic confidence in evaluation of brain metastases.
  • Yuri Yoshida, Satoshi Terae, Kohsuke Kudo, Khin Khin Tha, Masahiro Imamura, Kazuo Miyasaka
    JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 30 (6) 980 - 982 0363-8715 2006/11 [Refereed][Not invited]
     
    A case of brain stem capillary telangiectasia diagnosed by susceptibility-weighted imaging is reported. A small enhancing pontine lesion was found on postcontrast T1 -weighted MR images in a 56-year-old woman with human T-cell leukemia virus type I infection. Imaging diagnosis was difficult with conventional MR imaging because the lesion did not show characteristic signal loss on conventional gradient-echo images. SWI was useful for imaging diagnosis as it demonstrated marked signal loss of the lesion.
  • O. Ikeda, S. Kusunoki, K. Kudoh, H. Takamori, T. Tsuji, K. Kanemitsu, Y. Yamashita
    CardioVascular and Interventional Radiology 29 (3) 362 - 370 0174-1551 2006/06 [Refereed][Not invited]
     
    Purpose: To evaluate the effects of combined continuous transcatheter arterial infusion (CTAI) and systemic chemotherapy in patients with advanced pancreatic carcinoma. Methods: CTAI was performed in 17 patients with stage IV pancreatic cancer with (n = 11) or without (n = 6) liver metastasis. The reservoir was transcutaneously implanted with the help of angiography. The inferior pancreatic artery (IPA) was embolized to achieve delivery of the pancreatic blood supply through only the celiac artery. The systemic administration of gemcitabine was combined with the infusion of 5-fluorouracil via the reservoir. Treatment effects were evaluated based on the primary tumor size, liver metastasis, and survival time and factors such as tumor size, tumor location, and stage of pancreatic carcinoma the embolized arteries were analyzed with respect to treatment effects and prognosis. Results: A catheter was fixed in the gastroduodenal artery and splenic artery in 10 and 7 patients, respectively. Complete peripancreatic arterial occlusion was successful in 10 patients. CT showed a decrease in tumor size in 6 of 17 (35%) patients and a decrease in liver metastases in 6 of 11 (55%) patients. The survival time ranged from 4 to 18 months (mean ± SD, 8.8 ± 1.5 months). Complete embolization of arteries surrounding the pancreas was achieved in 10 patients they manifested superior treatment effects and prognoses (p < 0.05). Conclusion: In patients with advanced pancreatic cancer, long-term CTAI with systemic chemotherapy appeared to be effective not only against the primary tumor but also against liver metastases. Patients with successfully occluded peripancreatic arteries tended to survive longer. © Springer Science+Business Media, Inc. 2006.
  • [Repeated, reversible MR angiographic findings in pediatric moyamoya disease: case report].
    Toshiya Osanai, Satoshi Kuroda, Tatsuya Ishikawa, Kohsuke Kudo, Satoshi Terae, Masanori Isobe, Yoshinobu Iwasaki
    No shinkei geka. Neurological surgery 34 (4) 403 - 7 0301-2603 2006/04 [Refereed][Not invited]
     
    The authors report a 6-year-old girl presented with headache and transient ischemic attack due to moyamoya disease. MR angiography (MRA) revealed that her symptoms were closely related to reversible deterioration of stenosis in the left middle cerebral artery (MCA). Deterioration of stenosis led to a decreased flow signal in the distal branches of the left MCA. MRA could also detect reversible stenotic changes in the right MCA, although she did not develop any neurological symptom. Although precise mechanism of reversible MR angiographic findings is still unknown, the phenomenon may play an important role in disease progression in pediatric patients with moyamoya disease.
  • SASAKI M
    International Congress Series 1290 30 - 36 2006 [Refereed][Not invited]
  • New technique for visualizing cerebral vessels in MR angiographic images using three-dimensional discrete wavelet transform.
    Hongying Zuo, Shigehito Suzuki, Minoru Sotoda, Masahito Uesugi, Kosuke Kudo
    Igaku butsuri : Nihon Igaku Butsuri Gakkai kikanshi = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics 26 (2) 65 - 74 1345-5354 2006 [Refereed][Not invited]
     
    Visualization techniques for magnetic resonance (MR) angiographic images are generally based on the projection ray concept; for example, maximum intensity projection (MIP) and volume rendering (VR). A new technique based on a different concept from projection rays is explored in this study: three-dimensional (3-D) discrete wavelet transforms are used for visualizing cerebral vessels in the MR angiographic image. This technique successfully visualizes cerebral vessels and represents the spatial relationship between the cerebral vessels, as in the case of VR. The proposed technique is, thus, indicated to be promising for visualizing cerebral vessels in 3-D MR angiographic images.
  • KK Tha, S Terae, K Kudo, T Yamamoto, S Hamada, A Ogata, H Sasaki, K Miyasaka
    JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 30 (1) 126 - 130 0363-8715 2006/01 [Refereed][Not invited]
     
    The authors report a case of subacute sclerosing pariencephalitis in which the diagnosis was suggested by high b-value diffusion-weighted imaging (DWI) findings. The signal abnormalities were located asymmetrically at bilateral cerebral corticosubcortical regions. High b-value DWI showed these signal abnormalities as marked hyperintensity with decreased apparent diffusion coefficient values. The signal abnormalities were difficult to identify on other magnetic resonance imaging sequences, including routine DWI. High b-value DWI could be valuable for earlier detection of subacute sclerosing panencephalitis.
  • Prevalence of asymptomatic microbleeds in patients with moyamoya disease.
    Tatsuya Ishikawa, Satoshi Kuroda, Naoki Nakayama, Satoshi Terae, Kousuke Kudou, Yoshinobu Iwasaki
    Neurologia medico-chirurgica 45 (10) 495 - 500 0470-8105 2005/10 [Refereed][Not invited]
     
    Basal moyamoya vessels are a potential source of hemorrhage in patients with moyamoya disease, but the etiology remains unclear. Symptomatic hemorrhage resulting from long-standing hemodynamic effects on pathologically dilated, fragile moyamoya vessels may be preceded by asymptomatic microbleeding in adult moyamoya disease patients, regardless of hemorrhagic or ischemic onset. T2*-weighted magnetic resonance (MR) imaging was used to investigate the presence of microbleeds in 27 adult patients with angiographically confirmed moyamoya disease, 21 females and six males aged 18-70 years (mean 40.8 +/- 15.7 years). Clinical diagnosis was intracranial bleeding in six patients, transient ischemic attack or cerebral infarction in 18, and asymptomatic in three. Asymptomatic microbleeds were detected in four of the 27 patients, two of six who initially presented with hemorrhagic events and two of 18 with ischemic onset. These microbleeds were located in the paraventricular white matter, temporal subcortex, and basal ganglia. The presence of microbleeds had no correlation with either patient age or duration from disease onset or diagnosis of disease. A large cohort study is needed to explore the significance of asymptomatic microbleeds in moyamoya disease.
  • Hidefumi Aoyama, Hiroki Shirato, Norio Katoh, Kohsuke Kudo, Takeshi Asano, Satoshi Kuroda, Tatsuya Ishikawa, Kazuo Miyasaka
    International journal of radiation oncology, biology, physics 62 (4) 1232 - 8 0360-3016 2005/07/15 [Refereed][Not invited]
     
    PURPOSE: To investigate the discrepancy between the arteriovenous malformations seen on magnetic resonance angiography (MRA) and on stereotactic digital subtracted angiography (DSA). METHODS AND MATERIALS: The target volume on stereotactic DSA (V(DSA)) and the target volume on MRA (V(MRA)) were separately delineated in 28 intracranial arteriovenous malformations. The coordinates of the center and the outer edges of V(DSA) and V(MRA) were calculated and used for the analyses. RESULTS: The standard deviations (mean value) of the displacement of centers of V(MRA) from V(DSA) were 2.67 mm (-1.82 mm) in the left-right direction, 3.23 mm (-0.08 mm) in the anterior-posterior direction, and 2.16 mm (0.91 mm) in the craniocaudal direction. V(MRA) covered less than 80% of V(DSA) in any dimensions in 9 cases (32%), although no significant difference was seen in the target volume between each method, with a mean value of 11.9 cc for V(DSA) and 12.3 cc for V(MRA) (p = 0.948). CONCLUSION: The shift of centers between each modality is not negligible. Considering no significant difference between V(DSA) and V(MRA), but inadequate coverage of the V(DSA) by V(MRA), it is reasonable to consider that the target on MRA might include the feeding artery and draining vein and possibly miss a portion of the nidus.
  • Emiko Kaito, Satoshi Terae, Ryoji Kobayashi, Kohsuke Kudo, Khin Khin Tha, Kazuo Miyasaka
    Pediatric radiology 35 (7) 722 - 7 0301-0449 2005/07 [Refereed][Not invited]
     
    We report on a child with B-cell lymphoma who developed hypertension and reversible posterior leukoencephalopathy syndrome (RPLS) after chemotherapy conducted during recovery from tumor lysis syndrome. After recovery from RPLS, the patient received further combination chemotherapy without recurrence of the neurological signs or symptoms suggestive of RPLS. Many etiological factors have been reported in the development of RPLS; however, little attention has been paid to tumor lysis syndrome as a contributory factor for RPLS. Tumor lysis syndrome can precipitate the development of RPLS in patients with hematological malignancies who are undergoing chemotherapy. Knowledge and awareness would help facilitate immediate management such as normalization of blood pressure and temporary cessation of chemotherapy, helping to avoid irreversible brain damage.
  • Early detection of global cerebral anoxia: Improved accuracy by high-b-value diffusion-weighted imaging with long echo time
    KK Tha, S Terae, T Yamamoto, K Kudo, C Takahashi, M Oka, S Uegaki, K Miyasaka
    AMERICAN JOURNAL OF NEURORADIOLOGY 26 (6) 1487 - 1497 0195-6108 2005/06 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Early and accurate detection of global cerebral anoxia is important for determination of prognosis and further management. We evaluated whether accuracy in early detection of global cerebral anoxia was improved by high-b-value diffusion-weighted imaging (DWI) with long echo time (TE).METHODS: Routine DWI (b = 1000 s/mm(2); TE = 139 ms), high-b-value DWI (b = 3000 s/mm(2); TE = 190 ms), T2-weighted imaging (T2WI), and fluid-attenuated inversion recovery (FLAIR) imaging were acquired in six patients who experienced cardiopulmonary arrest within 24 hours and six volunteers. Region of interest-based analysis was performed. Regions of interest of patients showing significant decrease in apparent diffusion coefficient (ADC)3 values than volunteers were considered abnormal. Three neuroradiologists independently assessed images of the patients for conspicuity of hyperintensity within regions of interest. Receiver operating characteristic (ROC) analysis was performed, and the area under the curve (Az) was compared among sequences and observers. Average contrast and contrast-to-noise ratios between abnormal regions of interest and regions of interest of normal surrounding parenchyma were calculated.RESULTS: For all observers, high-b-value DWIs achieved the largest Az, and FLAIR imaging the lowest Az. Az of routine DWI and T2WI were between these values. High-b-value DWI and FLAIR imaging showed no significant interobserver variation in Az, whereas routine DWI and T2WI did. High-b-value DWI also achieved the largest contrast and contrast-to-noise ratios.CONCLUSION. High-b-value DWI with long TE improved accuracy in early detection of global cerebral anoxia. Application of the sequence would facilitate early diagnosis.
  • Physiologic change in flow velocity and direction of dural venous sinuses with respiration: MR venography and flow analysis.
    Kohsuke Kudo, Satoshi Terae, Aki Ishii, Tokuhiko Omatsu, Takeshi Asano, Khin Khin Tha, Kazuo Miyasaka
    AJNR. American journal of neuroradiology 25 (4) 551 - 7 0195-6108 2004/04 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Blood flow of the internal jugular vein and intracranial venous sinuses is affected by respiratory state. The purpose of this study was to clarify the changes in flow velocity and direction and signal intensities of sigmoid sinuses on phase-contrast (PC) MR images obtained with regular breathing and with deep inspiratory breath holding. METHODS: One hundred seven subjects without venous sinus abnormality were studied. Coronal 2D PC MR venography and axial 2D PC images with peripheral pulse gating were acquired with a 1.5-T MR unit, during regular breathing and deep inspiratory breath holding. The signal intensity changes of bilateral sigmoid sinuses on MR venograms and the changes of flow velocity and direction on the axial 2D PC images were analyzed. RESULTS: Breath holding decreased signal intensities of the right and left sigmoid sinuses on MR venograms in 57 (53.3%) and 36 (33.6%) subjects, respectively. Increased signal intensity was observed in 12 (11.2%) and 33 (30.8%) subjects, respectively. In the flow analysis, retrograde flow was detected at the left sigmoid sinus in four subjects (3.7%) during regular breathing, which was normalized by breath holding. Flow velocities of the right and left sigmoid sinuses decreased during breath holding in 92 (86.0%) and 70 (65.4%) subjects, and increased in 15 (14.0%) and 37 (34.6%) subjects, respectively. CONCLUSION: The signal intensities of sigmoid sinuses were affected by breath holding in about 2/3 of the subjects. Breath-holding maneuver can be used to increase blood flow and signal intensities of dural venous sinuses on PC MR venograms.
  • S Terae, K Kudo, T Asano, S Ushikoshi, K Hida, Y Iwasaki, K Miyasaka
    CLINICAL IMAGING 28 (1) 23 - 27 0899-7071 2004/01 [Refereed][Not invited]
     
    We performed intravenous CT angiography using multidetector-row helical computed tomography (MDCT) in a 63-year-old man with spinal arteriovenous malformation (AVM). The CT angiography demonstrated feeding arteries, varix-like structure, draining veins and their relationship to the spinal cord. Although selective angiography is essential in planning treatment for spinal AVMs as well as in establishing the diagnosis of the disease, CT angiography can be a good supplementary technique for visualizing precise location of abnormal vessels in a certain case of spinal AVM. (C) 2004 Elsevier Inc. All rights reserved.
  • MRI in methotrexate-related leukoencephalopathy: Disseminated necrotising leukoencephalopathy in comparison with mild leukoencephalopathy.
    M Oka, S Terae, R Kobayashi, Y Sawamura, K Kudoh, K K Tha, M Yoshida, M Kaneda, Y Suzuki, K Miyasaka
    Neuroradiology 45 (7) 493 - 7 0028-3940 2003/07 [Refereed][Not invited]
     
    We report two fatal cases of methotrexate (MTX)-induced disseminated necrotising leukoencephalopathy (DNL) in which MRI was repeated from the onset. Initial T2-weighted images showed multiple areas of high signal, mainly in deep cerebral white matter, which on follow-up, spread and coalesced to involve the entire white matter. Small irregular low-signal foci on T2-weighted images were seen within the high-signal lesions. Multiple areas of contrast enhancement corresponded to these low-signal foci. The condition of both patients deteriorated and they died. We compared their MRI findings with those of seven patients with mild MTX-related leukoencephalopathy, six of whom were asymptomatic; one had transient neurological symptoms. They showed no contrast enhancement, but rather mild-to-moderate diffuse high signal in deep white matter, which later disappeared. These findings suggest that multiple low-signal foci on T2-weighted images with contrast enhancement may be characteristic of DNL, and that contrast-enhanced imaging is useful to differentiate this condition from mild leukoencephalopathy.
  • Quantitative cerebral blood flow measurement with dynamic perfusion CT using the vascular-pixel elimination method: comparison with H2(15)O positron emission tomography.
    Kohsuke Kudo, Satoshi Terae, Chietsugu Katoh, Masaki Oka, Tohru Shiga, Nagara Tamaki, Kazuo Miyasaka
    AJNR. American journal of neuroradiology 24 (3) 419 - 26 0195-6108 2003/03 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Blood vessels are usually conspicuous on dynamic CT perfusion images. The presence of large vessels may lead to overestimation of the quantitative value of cerebral blood flow (CBF). We evaluated the efficacy of the vascular-pixel elimination (VPE) method in quantitative CT perfusion imaging, in comparison with positron emission tomography (PET). METHODS: Five healthy volunteers underwent CT perfusion and PET studies. A four-channel multi-detector row CT scanner was used. Dynamic cine scanning was performed after bolus injection of an intravenous contrast agent. CT-CBF was calculated by the central volume principle and deconvolution method. PET was performed after infusion of (15)O-labeled water. PET-CBF was calculated by using a nonlinear least squares method. Average CBF values of the whole section, gray matter, and white matter with both CT and PET were compared after image registration. The comparison was performed with and without VPE. In the VPE method, the vascular pixels were defined by the cerebral blood volume value of the pixel. The threshold of VPE was changed from 5 to 20 mL/100 g. Pixel-by-pixel correlation between CT-CBF and PET-CBF and linear regression analysis were also performed. RESULTS: Without VPE, CT-CBF was overestimated in all subjects. As the VPE threshold decreased, CT-CBF decreased and the correlation coefficient increased. The best correlation was observed at a VPE threshold of 8 mL/100 g in four of the five subjects. Average CT-CBF values, without VPE, of the whole section, gray matter, and white matter were 59.01, 66.73, and 42.53 mL/100 g/min, respectively. With VPE (threshold, 8 mL/100 g), average CT-CBF values of the whole section, gray matter, and white matter were 45.56, 52.75, and 30.38, respectively. The corresponding PET-CBF values were 46.86, 50.89, and 38.20 mL/100 g/min, respectively. CONCLUSION: Vascular pixels should be excluded from the calculation of CT-CBF to avoid overestimation of the CBF values. If vascular pixels are excluded, CBF calculation with CT perfusion imaging is considerably accurate.
  • Anterior spinal artery and artery of Adamkiewicz detected by using multi-detector row CT.
    Kohsuke Kudo, Satoshi Terae, Takeshi Asano, Masaki Oka, Kenshi Kaneko, Satoshi Ushikoshi, Kazuo Miyasaka
    AJNR. American journal of neuroradiology 24 (1) 13 - 7 0195-6108 2003/01 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Our purpose was to evaluate the visualization of the artery of Adamkiewicz (AKA) and the anterior spinal artery (ASA) by using multi-detector row CT. Preoperative detection of the AKA and ASA is important for prevention of ischemic complications of thoracoabdominal aortic surgery. METHODS: Data from contrast-enhanced CT of the abdomen of 19 consecutive patients with known or suspected liver disease were evaluated. The scanning range was set from the level of the diaphragm to the lower edge of the liver. After bolus injection of contrast material (100 mL of iohexol, 350 mgI/mL, 5 mL/s), arterial phase scans were obtained by using a four-channel multi-detector row CT scanner. The scanning parameters included a detector row configuration of 4 x 2 mm, a pitch of 5:1, a gantry rotation speed of 0.5 s, 120 kVp, and 150 mAs. Arterial phase coronal multiplanar reconstruction scans obtained parallel to the spinal cord were evaluated by two neuroradiologists. The detectability of ASA and AKA was analyzed. RESULTS: The AKA was visualized on the scans of 13 of 19 patients (68%). The segmental level of AKA origin ranged from T10 to L2. The AKA originated from the left side in nine patients (69%) and the right side in four patients (31%). The ASA was visualized on the scans of all patients (100%). For 16 of the 19 patients, the ASA was detected in its full length from the cranial edge of the scan range. However, the ascending branch of the ASA distal to the junction of the AKA was not detected for the remaining three patients. CONCLUSION: The AKA and ASA can be visualized by using multi-detector row CT with the use of IV administered contrast material. Multi-detector row CT could be a useful tool in the evaluation of spinal vascular structures.
  • Diffusion-weighted magnetic resonance imaging in early stage of 5-fluorouracil-induced leukoencephalopathy.
    K K Tha, S Terae, M Sugiura, T Nishioka, M Oka, K Kudoh, K Kaneko, K Miyasaka
    Acta neurologica Scandinavica 106 (6) 379 - 86 0001-6314 2002/12 [Refereed][Not invited]
     
    We report a case of 5-fluorouracil (5-FU)-induced leukoencephalopathy in which magnetic resonance imaging (MRI) of the brain, including diffusion-weighted imaging (DWI), was performed serially. The initial T2-weighted and FLAIR images showed diffuse mild hyperintensity in bilateral deep cerebral white matter and corpus callosum, which on T1WI appeared as non-enhanced faint hypointensity. Isotropic DWI disclosed the abnormality as well-conspicuous diffuse hyperintensity with decreased ADC. Serial studies revealed that majority of the abnormal signal intensity on these sequences resolved, and the decreased ADC values approached normal. Some hyperintensity remained in the deep cerebral white matter and the splenium, but no further significant ADC change after normalization was noted. Measurement of ADC along the three orthogonal directions showed the presence of directional dependence of diffusion throughout the length of study. These findings suggest that early stage of 5-FU-induced leukoencephalopathy is associated with reversible restricted diffusion and preservation of anisotropy. Diffusion-weighted imaging may be useful for the diagnosis.
  • Diffusion-weighted MR findings in a reversible case of acute Wernicke encephalopathy.
    M Oka, S Terae, R Kobayashi, K Kudoh, B C Chu, K Kaneko, M Yoshida, M Kaneda, Y Suzuki, K Miyasaka
    Acta neurologica Scandinavica 104 (3) 178 - 81 0001-6314 2001/09 [Refereed][Not invited]
     
    We report a case of acute Wernicke encephalopathy (WE) in which apparent diffusion coefficient maps showed areas of increased diffusion in the bilateral medial thalami that corresponded to the hyperintense lesions on T2-weighted imaging. The hyperintense lesions on T2-weighted imaging disappeared with full recovery from symptoms. These findings suggest that the hyperintense lesions of the acute changes of WE include reversible vasogenic edema and are not caused by acute ischemia.
  • Wavelet compression on detection of brain lesions with magnetic resonance imaging.
    S Terae, K Miyasaka, K Kudoh, T Nambu, T Shimizu, K Kaneko, H Yoshikawa, R Kishimoto, T Omatsu, N Fujita
    Journal of digital imaging 13 (4) 178 - 90 0897-1889 2000/11 [Refereed][Not invited]
     
    The purpose of this report is to assess clinically acceptable compression ratios on the detection of brain lesions at magnetic resonance imaging (MRI). Four consecutive T2-weighted and the corresponding T1-weighted images obtained in 20 patients were studied for 109 anatomic sites including 50 with lesions and 59 without lesions. The images were obtained on a 1.5-T MR unit with a pixel size of 0.9 to 1.2 x 0.47 mm and a section thickness of 5 mm. The image data were compressed by wavelet-based algorithm at ratios of 20:1, 40:1, and 60:1. Three radiologists reviewed these images on an interactive workstation and rated the presence or absence of a lesion with a 50 point scale for each anatomic site. The authors also evaluated the influence of pixel size on the quality of image compression. At receiver operating characteristic (ROC) analysis, no statistically significant difference was detected at a compression ratio of 20:1. A significant difference was observed with 40:1 compressed images for one reader (P = .023), and with 60:1 for all readers (P = .001 to .012). A root mean squared error (RMSE) was higher in 0.94- x 0.94-mm pixel size images than in 0.94- x 0.47-mm pixel size images at any compression ratio, indicating compression tolerance is lower for the larger pixel size images. The RMSE, subjective image quality, and error images of 10:1 compressed 0.94- x 0.94-mm pixel size images were comparable with those of 20:1 compressed 0.94- x 0.47-mm pixel size images. Wavelet compression can be acceptable clinically at ratios as high as 20:1 for brain MR images when a pixel size at image acquisition is around 1.0 x 0.5 mm, and as high as 10:1 for those with a pixel size around 1.0 x 1.0 mm.
  • H Shirato, S Shimizu, T Kunieda, K Kitamura, M van Herk, K Kagei, T Nishioka, S Hashimoto, K Fujita, H Aoyama, K Tsuchiya, K Kudo, K Miyasaka
    International journal of radiation oncology, biology, physics 48 (4) 1187 - 95 0360-3016 2000/11/01 [Refereed][Not invited]
     
    PURPOSE: To reduce uncertainty due to setup error and organ motion during radiotherapy of tumors in or near the lung, by means of real-time tumor tracking and gating of a linear accelerator. METHODS AND MATERIALS: The real-time tumor-tracking system consists of four sets of diagnostic X-ray television systems (two of which offer an unobstructed view of the patient at any time), an image processor unit, a gating control unit, and an image display unit. The system recognizes the position of a 2.0-mm gold marker in the human body 30 times per second using two X-ray television systems. The marker is inserted in or near the tumor using image guided implantation. The linear accelerator is gated to irradiate the tumor only when the marker is within a given tolerance from its planned coordinates relative to the isocenter. The accuracy of the system and the additional dose due to the diagnostic X-ray were examined in a phantom, and the geometric performance of the system was evaluated in 4 patients. RESULTS: The phantom experiment demonstrated that the geometric accuracy of the tumor-tracking system is better than 1.5 mm for moving targets up to a speed of 40 mm/s. The dose due to the diagnostic X-ray monitoring ranged from 0.01% to 1% of the target dose for a 2.0-Gy irradiation of a chest phantom. In 4 patients with lung cancer, the range of the coordinates of the tumor marker during irradiation was 2.5-5.3 mm, which would have been 9.6-38.4 mm without tracking. CONCLUSION: We successfully implemented and applied a tumor-tracking and gating system. The system significantly improves the accuracy of irradiation of targets in motion at the expense of an acceptable amount of diagnostic X-ray exposure.
  • Wavelet compression on detection of brain lesions at MR imaging in teleradiology
    S Terae, K Miyasaka, K Kudoh, T Nambu, H Yoshikawa, T Shimizu, N Fujita
    CAR '98 - COMPUTER ASSISTED RADIOLOGY AND SURGERY 1165 459 - 463 0531-5131 1998 [Refereed][Not invited]
     
    This report describes an receiver operating characteristic (ROC) analysis of magnetic resonance (MR) images before and after wavelet-based compression on the detection of brain lesions. No statistically significant differences in the area under the ROC curves (Az) were found between the original and 20:1 compressed images. Wavelet technology is a promising compression tool for transmission of MR images in direct digital form.
  • Detectability of simulated nodules on chest phantom by liquid crystal monitor
    T Nambu, K Kudoh, K Miyasaka
    CAR '98 - COMPUTER ASSISTED RADIOLOGY AND SURGERY 1165 958 - 958 0531-5131 1998 [Refereed][Not invited]

MISC

  • MRI構造画像と磁化率画像に基づくアルツハイマー病の診断指標
    佐藤 良太, 工藤 與亮, 河田 康雄, 宇土 仁木, 松島 理明, 矢部 一郎, 山口 晃典, 尾藤 良孝, 越智 久晃, 白猪 亨  Dementia Japan  33-  (4)  553  -553  2019/10  [Not refereed][Not invited]
  • Haruna Watanabe, Ren Togo, Takahiro Ogawa, Miki Haseyama, Koichi Yasuda, Khin Khin Tha, Kohsuke Kudo, Hiroki Shirato  Proceedings of SPIE - The International Society for Optical Engineering  11050-  2019/01/01  [Not refereed][Not invited]
     
    © 2019 SPIE. In this paper, we propose a method to classify metastatic bone tumors using treatment-planning computed tomography images. The proposed method utilizes pre-trained deep convolutional neural network (DCNN) models as feature extractors and enables the metastatic bone tumor classification by using the obtained features. Performance of several state-of-the-art DCNN-based features was compared and evaluated in our experiment.
  • IVW-MRIが治療効果判定に有用であった中枢神経限局性血管炎
    井上 知彦, 水島 慶一, 工藤 彰彦, 佐藤 翔紀, 佐藤 智香, 長沼 亮滋, 上床 尚, 白井 慎一, 高橋 育子, 松島 理明, 矢部 一郎, 原田 太以佑, 工藤 與亮, 佐々木 秀直  臨床神経学  58-  (Suppl.)  S456  -S456  2018/12  [Not refereed][Not invited]
  • 多系統萎縮症におけるプロトン密度強調画像を用いた小脳の信号強度の検討
    山口 晃典, 原田 太以佑, 松島 理明, 矢部 一郎, 佐々木 秀直, 工藤 與亮  臨床神経学  58-  (Suppl.)  S241  -S241  2018/12  [Not refereed][Not invited]
  • IVW-MRIが治療効果判定に有用であった中枢神経限局性血管炎
    井上 知彦, 水島 慶一, 工藤 彰彦, 佐藤 翔紀, 佐藤 智香, 長沼 亮滋, 上床 尚, 白井 慎一, 高橋 育子, 松島 理明, 矢部 一郎, 原田 太以佑, 工藤 與亮, 佐々木 秀直  臨床神経学  58-  (Suppl.)  S456  -S456  2018/12  [Not refereed][Not invited]
  • 森田亮, 阿保大介, 曽山武士, 工藤與亮, 白土博樹, 作原祐介  IVR  33-  (3)  314  2018/11/25  [Not refereed][Not invited]
  • 渡邊はるな, 藤後廉, 小川貴弘, 長谷山美紀, 安田耕一, THA Khin Khin, 工藤與亮, 白土博樹  電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2018-  ROMBUNNO.87  2018/10/27  [Not refereed][Not invited]
  • 腹臥位での腰仙椎MRIが診断に有用であった脊髄係留症候群の1例
    水島 慶一, 佐藤 翔紀, 工藤 彰彦, 佐藤 智香, 長沼 亮滋, 上床 尚, 白井 慎一, 高橋 育子, 松島 理明, 矢部 一郎, 原田 太以佑, 工藤 與亮, 濱内 祝嗣, 関 俊隆, 佐々木 秀直  臨床神経学  58-  (5)  358  -358  2018/05  [Not refereed][Not invited]
  • 腹臥位での腰仙椎MRIが診断に有用であった脊髄係留症候群の1例
    水島 慶一, 佐藤 翔紀, 工藤 彰彦, 佐藤 智香, 長沼 亮滋, 上床 尚, 白井 慎一, 高橋 育子, 松島 理明, 矢部 一郎, 原田 太以佑, 工藤 與亮, 濱内 祝嗣, 関 俊隆, 佐々木 秀直  臨床神経学  58-  (5)  358  -358  2018/05  [Not refereed][Not invited]
  • 貼付剤によるRF heating 位置依存性の検証
    石坂 欣也, 堀江 達則, 工藤 與亮  北海道放射線技術雑誌  (84)  20  -21  2018/03  [Not refereed][Not invited]
  • 菅田健斗, 小川貴弘, 長谷山美紀, THA Khin Khin, THA Khin Khin, 工藤與亮, 工藤與亮, 白土博樹, 白土博樹  電子情報通信学会技術研究報告  117-  (431)  311  -314  2018/02/15  [Not refereed][Not invited]
  • 術前診断に苦慮した、骨盤底部から臀部に発生した嚢胞性病変の1例
    中村 友亮, 菊池 穏香, 加藤 扶美, 藪崎 哲史, 坂本 圭太, 三村 理恵, 真鍋 徳子, 工藤 與亮, 岡田 宏美, 本間 重紀, 吉田 雅, 川村 秀樹  Japanese Journal of Radiology  36-  (Suppl.)  17  -17  2018/02  [Not refereed][Not invited]
  • 菅田 健斗, 小川 貴弘, 長谷山 美紀, タ キンキン, 工藤 與亮, 白土 博樹  映像情報メディア学会技術報告 = ITE technical report  42-  (4)  311  -314  2018/02  [Not refereed][Not invited]
  • 菊池穏香, 吉野裕紀, 工藤與亮, 工藤與亮, 加藤扶美, 加藤扶美, 南須原康行, 南須原康行, 南須原康行, 品川尚文, 清水康, 田中敏, 兵頭秀樹, 的場光太郎, 的場光太郎, 三上八郎, 田中伸哉, 田中伸哉, 白土博樹, 白土博樹  日本医学放射線学会秋季臨床大会抄録集  53rd-  S506  2017/08/18  [Not refereed][Not invited]
  • MRIによる子宮体癌と子宮癌肉腫の鑑別に関する検討
    常田 慧徳, 加藤 扶美, 朝野 拓史, 野崎 綾子, 井平 圭, 三田村 卓, 金野 陽輔, 加藤 達矢, 渡利 英道, 飯嶋 由紀, 西岡 井子, 真鍋 徳子, 工藤 與亮  日本医学放射線学会秋季臨床大会抄録集  53回-  S470  -S471  2017/08  [Not refereed][Not invited]
  • 肝腫瘍に対する動態追跡照射のための経皮的マーカ留置
    森田 亮, 曽山 武士, 阿保 大介, 作原 祐介, 工藤 與亮, 加藤 徳雄, 白土 博樹  IVR: Interventional Radiology  32-  (2)  161  -161  2017/07  [Not refereed][Not invited]
  • 成人発症のAlexander病の1例
    阿部 恵, 西村 洋昭, 長沼 亮滋, 白井 慎一, 高橋 育子, 松島 理明, 加納 崇裕, 矢部 一郎, 原田 太以佑, 藤間 憲幸, 工藤 與亮, 吉田 誠克, 佐々木 秀直  臨床神経学  57-  (6)  322  -322  2017/06  [Not refereed][Not invited]
  • 野村順一, 上野育子, 佐々木真理, 工藤與亮, 山下典生, 伊藤賢司, 松本昌泰, 及川公樹, 藤原俊朗, 千田光平, 寺崎一典, 小林正和, 吉田研二, 小笠原邦昭  日本心血管脳卒中学会学術集会プログラム・抄録集  4th-  162  2017/04/24  [Not refereed][Not invited]
  • 肝腫瘍に対する動態追跡照射のための経皮的マーカ留置(Percutaneous hepatic fiducial marker implantation for Real-time Tumor-tracking Radiotherapy(RTRT))
    森田 亮, 作原 祐介, 曽山 武士, 阿保 大介, 加藤 徳雄, 工藤 與亮, 白土 博樹  IVR: Interventional Radiology  32-  (Suppl.)  173  -173  2017/04  [Not refereed][Not invited]
  • 胆・膵悪性腫瘍術後の症候性門脈狭窄に対する経皮経肝的門脈ステント留置の検討
    木村 輔, 森田 亮, 曽山 武士, 阿保 大介, 作原 祐介, 工藤 與亮, 神山 俊哉, 平野 聡  IVR: Interventional Radiology  32-  (1)  79  -79  2017/03  [Not refereed][Not invited]
  • 18F-FDG PET/CTにより経過を追うことができた顆粒球肉腫の1例
    藤井 宝顕, 真鍋 治, 平田 健司, 渡邊 史郎, 真鍋 徳子, 工藤 與亮, 志賀 哲  核医学  54-  (1)  652  -652  2017/02  [Not refereed][Not invited]
  • 画像診断に苦慮したHHV8-unrelated primary effusion lymphoma-like lymphomaの1例
    中川 純一, 加藤 扶美, 三村 理恵, 藪崎 哲史, 坂本 圭太, 真鍋 徳子, 工藤 與亮, 菅野 宏美, 松野 吉宏, 豊嶋 崇徳, 金谷 穣, 渡利 英道, 櫻木 範明, 白土 博樹  Japanese Journal of Radiology  35-  (Suppl.)  3  -3  2017/02  [Not refereed][Not invited]
  • DW-ASLを用いた脳虚血領域におけるwater permeabilityの評価
    藤間 憲幸, 奥秋 知幸, 青池 拓哉, 青池 寿々子, 杉森 博行, 工藤 與亮  日本磁気共鳴医学会雑誌  37-  (1)  15  -17  2017/02  [Not refereed][Not invited]
     
    脳虚血性病変を有する8例(男性7名、女性1名、53〜73歳)を対象とした。5例はdiffusion-weighted arterial spin labelingの撮像日の3年前に全脳のT2強調像、FLAIR像での評価を行った。それぞれのROIごとにT2強調像、FLAIR像で虚血の程度に応じて、3段階のグレード評価を行い、殆ど虚血を認めないNI群、虚血性変化が軽度のMI群、虚血性変化が中等度ないし高度のSI群に分けた。それぞれのROIごとに虚血の変化を比較して虚血の変化に応じて二つのグレードに分割した(NP群;3年間で虚血が殆ど変化なし、P群;3年間で虚血が拡大)。DW-ASLの撮像は問題なく施行可能であった。104個のROIによる3段階の虚血の程度の評価に関してKw値を算出し、SI群はMI群、NI群と比較して有意に高かった。3年間の虚血の進行の程度に関しては、5例における65個のROIの評価の結果、P群はNP群と比較して、有意にKwの値が高かった。視覚的にはT2強調像やFLAIR像で認める高信号域よりやや広い領域でwater permeabilityの変化がみられる領域が観察される傾向があった。
  • 野村順一, 上野育子, 佐々木真理, 工藤與亮, 山下典生, 伊藤賢司, 松本昌泰, 及川公樹, 藤原俊朗, 千田光平, 寺崎一典, 小林正和, 吉田研二, 小笠原邦昭  脳循環代謝(Web)  29-  (1)  169  2017  [Not refereed][Not invited]
  • PD後破裂挙上空腸静脈瘤に対し経空腸静脈的塞栓術にて救命した1例
    阿保 大介, 木村 輔, 曽山 武士, 作原 祐介, 森田 亮, 工藤 與亮, 田本 英司, 岡村 圭祐, 平野 聡  IVR: Interventional Radiology  31-  (4)  376  -376  2017/01  [Not refereed][Not invited]
  • 山口晃典, 加藤扶美, 加藤達矢, 清水亜衣, 松野吉宏, 真鍋徳子, 井平圭, 野崎綾子, 渡利英道, 工藤與亮  Abstracts. Annual Symposium. Japanese Society for the Advancement of Women’s Imaging  18th-  73‐74  2017  [Not refereed][Not invited]
  • 加藤扶美, 井平圭, 野崎綾子, 中智昭, 松野吉宏, 渡利英道, 真鍋徳子, 工藤與亮  Abstracts. Annual Symposium. Japanese Society for the Advancement of Women’s Imaging  18th-  64  2017  [Not refereed][Not invited]
  • 骨髄MRI T1 map値は海綿骨強度予測のための間接的骨質指標となる
    遠藤香織, 高畑雅彦, 杉森博行, Wang Jeffrey, 山田悟史, 伊藤陽一, 高橋大介, 清水智弘, 東藤正浩, 但野茂, 工藤與亮, 岩崎倫政  日本整形外科学会雑誌  90-  (8)  S1732  -S1732  2016/08  [Not refereed][Not invited]
  • 骨髄MRI T1 map値は海綿骨強度予測のための間接的骨質指標となる
    遠藤 香織, 高畑 雅彦, 杉森 博行, Wang Jeffrey, 山田 悟史, 伊藤 陽一, 高橋 大介, 清水 智弘, 東藤 正浩, 但野 茂, 工藤 與亮, 岩崎 倫政  日本整形外科学会雑誌  90-  (8)  S1732  -S1732  2016/08  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 曽山武士, 森田亮, 工藤與亮  Rad Fan  14-  (9)  45‐48  -48  2016/07/29  [Not refereed][Not invited]
     
    腫大による圧迫や疼痛などの症状を呈する嚢胞性腫瘤(parasitic cystic lesionsを除く)に対する経皮的治療として、簡便性からまず画像ガイド下穿刺吸引・ドレナージカテーテル留置が行われる。しかし吸引のみではしばしば再発するため、同時に硬化療法が行われることも多い。本稿では肝嚢胞、腎嚢胞、リンパ嚢胞に対する経皮的硬化療法について、文献的考察を交えて概説する。(著者抄録)
  • 宮本憲幸, 薮崎哲史, 加藤扶美, 真鍋徳子, 木村輔, 吉野裕紀, 高橋文也, 曽山武士, 阿保大介, 作原祐介, 工藤與亮  IVR  31-  (2)  174  2016/06/20  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 曽山武士, 高橋文也, 木村輔, 工藤與亮, 西尾妙織  IVR  31-  (2)  175  2016/06/20  [Not refereed][Not invited]
  • 下腹壁仮性動脈瘤に対しNBCAを楔入下注入し塞栓した1例
    高橋 文也, 阿保 大介, 豊永 拓哉, 木村 輔, 曽山 武士, 作原 祐介, 工藤 與亮, 中村 透, 岡村 圭祐, 平野 聡  IVR: Interventional Radiology  31-  (2)  175  -176  2016/06  [Not refereed][Not invited]
  • FPD搭載IVRシステム導入後のHCCに対する超選択的Lip-TACEの治療成績
    阿保 大介, 作原 祐介, 曽山 武士, 高橋 文也, 木村 輔, 工藤 與亮, 柿坂 達彦, 横尾 英樹, 神山 俊哉, 荘 拓也, 小川 浩司  IVR: Interventional Radiology  31-  (2)  175  -175  2016/06  [Not refereed][Not invited]
  • 3T乳腺MRIにおける拡散尖度画像を用いた浸潤性乳癌の評価 バイオマーカーおよび腋窩リンパ節転移との比較
    加藤 扶美, 工藤 與亮, 藤原 太郎, Wang Jeff, 杉森 博行, 山下 啓子, 細田 充主, 真鍋 徳子, 三村 理恵, 白土 博樹  日本乳癌学会総会プログラム抄録集  24回-  250  -250  2016/06  [Not refereed][Not invited]
  • 【胆膵疾患における血管系IVR】 膵切除時の血流改変 手技を中心に
    阿保 大介, 作原 祐介, 曽山 武士, 森田 亮, 工藤 與亮, 田本 英司, 中村 透, 平野 聡  胆と膵  37-  (5)  427  -432  2016/05  [Not refereed][Not invited]
     
    当科では局所進行膵体部癌に対する腹腔動脈合併尾側膵切除術(Distal pancreatectomy with en-bloc celiac axis resection:DP-CAR)前に術後虚血性合併症の予防・低減を目的に総肝動脈塞栓術を行っている。当初はInterlocking detachable coil(IDC)を単独カテーテルで用いる塞栓術方法であった。種々の方法の試行の後、2本のマイクロカテーテルで2本のIDCを同時に絡めながら塞栓するDMDI法を開発・適応することで、方法の変更なく確実な総肝動脈塞栓術が可能となった。最近ではAmplatzer Vascular Plug4が使用可能となり、その位置安定性と運搬の容易さから適応症例の増加が見込まれている。さまざまなデバイスを柔軟に使い分け、IVRによる合併症を起こさずに確実に成功させるよう努めていくことが肝要である。(著者抄録)
  • FPD搭載IVRシステム導入後のHCCに対する超選択的Lip-TACEの局所再発率の検討
    阿保 大介, 作原 祐介, 曽山 武士, 木村 輔, 森田 亮, 工藤 與亮  IVR: Interventional Radiology  31-  (Suppl.)  157  -157  2016/04  [Not refereed][Not invited]
  • ステアリングマイクロカテーテルの初期使用経験
    曽山 武士, 阿保 大介, 吉田 大介, 木村 輔, 森田 亮, 作原 祐介, 工藤 與亮  IVR: Interventional Radiology  31-  (Suppl.)  214  -214  2016/04  [Not refereed][Not invited]
  • 球状塞栓物質を用いた子宮動脈塞栓術後に卵巣機能低下を呈した1例
    中川 純一, 森田 亮, 曽山 武士, 作原 祐介, 木村 輔, 阿保 大介, 工藤 與亮  IVR: Interventional Radiology  31-  (Suppl.)  219  -219  2016/04  [Not refereed][Not invited]
  • MDCTによる膵神経内分泌腫瘍(PNET)の組織学的grade、肝転移に関する検討
    宮本 憲幸, 坂本 圭太, 藪崎 哲史, 亀田 浩之, 豊永 拓哉, 吉野 裕紀, 木村 輔, 菊池 穏香, 三村 理恵, 加藤 扶美, 真鍋 徳子, 工藤 與亮, 土川 貴裕, 中村 透, 岡村 圭祐, 平野 聡  Japanese Journal of Radiology  34-  (Suppl.)  13  -13  2016/02  [Not refereed][Not invited]
  • 3T乳腺MRIにおける拡散尖度画像の検討
    加藤 扶美, 工藤 與亮, 三村 理恵, 藪崎 哲史, 坂本 圭太, 宮本 憲幸, 真鍋 徳子, 藤原 太郎, 杉森 博行, 山下 啓子, 細田 充主, Wang Jeff, 白土 博樹  Japanese Journal of Radiology  34-  (Suppl.)  13  -13  2016/02  [Not refereed][Not invited]
  • 曽山武士, 作原祐介, 坂本圭太, 高橋文也, 阿保大介, 工藤與亮, 一山芽衣, 渥美達也, 新井隆太, 岩崎倫政  IVR  30-  (3)  275  2015/09/20  [Not refereed][Not invited]
  • 既存ドレーン経路と経皮的空腸瘻造設により経皮的に治療した膵液瘻の1例
    阿保 大介, 吉野 裕紀, 高橋 文也, 曽山 武士, 作原 祐介, 工藤 與亮, 蒲池 浩文, 折茂 達也, 若山 顕治, 柿坂 達彦, 敦賀 陽介, 横尾 英樹, 神山 俊哉  IVR: Interventional Radiology  30-  (3)  271  -271  2015/09  [Not refereed][Not invited]
  • 膵切除後膵液漏発生に関するMRIを用いた残膵性状評価
    宮本 憲幸, 藪崎 哲史, 加藤 扶美, 高橋 文也, 曽山 武士, 阿保 大介, 作原 祐介, 工藤 與亮, 中村 透, 松本 譲, 岡村 圭祐, 平野 聡  IVR: Interventional Radiology  30-  (3)  268  -268  2015/09  [Not refereed][Not invited]
  • 胃全摘術後食道静脈瘤に対してPTOを施行した1例
    高橋 文也, 阿保 大介, 湊川 英樹, 作原 祐介, 曽山 武士, 工藤 與亮, 海老原 裕磨, 平野 聡  IVR: Interventional Radiology  30-  (3)  270  -271  2015/09  [Not refereed][Not invited]
  • 術前MRIによる膵頭部切除後膵液漏発生の検討
    宮本 憲幸, 坂本 圭太, 薮崎 哲史, 高橋 文也, 木村 輔, 亀田 浩之, 菊池 穏香, 三村 理恵, 加藤 扶美, 真鍋 徳子, 工藤 與亮, 白土 博樹, 中村 透, 松本 譲, 岡村 圭祐, 平野 聡  IVR: Interventional Radiology  30-  (3)  271  -271  2015/09  [Not refereed][Not invited]
  • Sorafenib導入後HCC症例に対する経動脈治療の検討
    吉野 裕紀, 阿保 大介, 作原 祐介, 高橋 文也, 曽山 武士, 工藤 與亮, 柿坂 達彦, 横尾 英樹, 神山 俊哉, 小川 浩司, 荘 拓也, 夏井坂 光輝  IVR: Interventional Radiology  30-  (3)  273  -273  2015/09  [Not refereed][Not invited]
  • 作原祐介, 阿保大介, 曽山武士, 工藤與亮, 西尾妙織, 長谷川悠  Rad Fan  13-  (9)  66  -69  2015/07/31  [Not refereed][Not invited]
  • Association of early tumor shrinkage with progression-free survival in patients with metastatic colorectal cancer treated with bevacizumab-based chemotherapy: HGCSG0802.
    Hiroshi Nakatsumi, Satoshi Yuki, Tetsuhito Muranaka, Hiraku Fukushima, Takashi Kato, Takashi Meguro, Michio Nakamura, Ichiro Iwanaga, Nobuyuki Ehira, Norikazu Sonoda, Mineo Kudo, Kanji Kato, Kencho Miyashita, Masakazu Abe, Noriyuki Miyamoto, Keita Sakamoto, Kohsuke Kudo, Naoya Sakamoto, Yuh Sakata, Yoshito Komatsu  JOURNAL OF CLINICAL ONCOLOGY  33-  (3)  2015/01  [Not refereed][Not invited]
  • 肝前区域切除術後に発症した胆管後区域枝完全閉塞に対し内瘻経路造設できた1例
    阿保 大介, 曽山 武士, 作原 祐介, 高橋 文也, 工藤 與亮, 横尾 英樹, 蒲池 浩文, 神山 俊哉  IVR: Interventional Radiology  29-  (Suppl.)  221  -221  2014/05  [Not refereed][Not invited]
  • KATO FUMI, KUDO KOSUKE, YAMASHITA HIROKO, HATANAKA KANAKO, HOSODA MICHITSUKA, MANABE NORIKO, YAMAMOTO MITSUGU, MIMURA RIE, MIYAMOTO NORIYUKI, SHIRATO HIROKI  日本乳癌学会学術総会プログラム・抄録集  22nd-  357  2014  [Not refereed][Not invited]
  • KATO FUMI, MANABE NORIKO, KUDO KOSUKE, YAMASHITA HIROKO, HOSODA MICHITSUKA, YAMAMOTO MITSUGU, HATANAKA KANAKO, SHIRATO HIROKI  北海道外科雑誌  58-  (2)  121  2013/12/20  [Not refereed][Not invited]
  • KATO FUMI, SUGIMORI HIROYUKI, MANABE NORIKO, KUDO KOSUKE  臨床画像  29-  (11)  1312  -1322  2013/11/26  [Not refereed][Not invited]
  • 真鍋徳子, 真鍋治, 納谷昌直, 菊池穏香, 工藤與亮, 玉木長良  核医学  50-  (3)  241  2013/09/30  [Not refereed][Not invited]
  • 7テスラMRIによる脳神経画像診断の新しい展開
    佐々木 真理, 工藤 與亮, 上野 育子, 椛沢 宏之, 松田 豪  BRAIN and NERVE: 神経研究の進歩  64-  (9)  1057  -1062  2012/09  [Not refereed][Not invited]
     
    7TMRIは高い信号雑音比を活かして脳神経領域の超高精細形態画像を得ることができる他、強い磁化率効果を利用して、T2強調画像、磁化率強調画像の大幅なコントラスト向上や、functional MRIの精度向上が可能となる。また、T1の延長はMRAやarterial spin labelingの大幅な画質向上や造影効果の向上に寄与し、化学シフトの増加はMR spectroscopyの分離能向上をもたらす。7TMRIの特徴・画像・将来について述べた。
  • Susceptibility Weighted Phase Imaging in Anesthetized and Non-Anesthetized Subjects Demonstrates Regional Differences in Oxygen Extraction Fraction in the Brain
    Jonathan Goodwin, Kohsuke Kudo, Yutaka Shinohe, Ikuko Uwano, Fumio Yamashita, Yutaka Matsumura, Tsuyoshi Metoki, Kuniaki Ogasawara, Akira Ogawa, Makoto Sasaki  CEREBROVASCULAR DISEASES  34-  42  -42  2012  [Not refereed][Not invited]
  • Detecting Intracranial Atherosclerotic Lesions in Acute Stroke Patients by Using Magnetic Resonance Three-Dimensional Vessel Wall Imaging (3D-VWI)
    Tatsunori Natori, Makoto Sasaki, Mitsuharu Miyoshi, Hideki Ohba, Noriyuki Katsura, Mao Yamaguchi, Shinsuke Narumi, Kohsuke Kudo, Yasuo Terayama  CEREBROVASCULAR DISEASES  34-  41  -41  2012  [Not refereed][Not invited]
  • 高橋哲彦, 板垣博幸, 瀧澤将宏, 西原崇, 森分周子, 工藤與亮, 佐々木真理  日立評論  93-  (3)  272  -275  2011/03/01  [Not refereed][Not invited]
  • 七戸秀夫, 黒田敏, 工藤與亮, 伊東雅基, 川堀真人, 宮本倫行, 宝金清博, 寺江聡  再生医療  10-  257  2011/02/01  [Not refereed][Not invited]
  • 吉田大介, 藤間憲幸, 財津有里, THA Khin Khin, 寺江聡, 白土博樹, 工藤與亮  Jpn J Radiol  29-  (Supplement 1)  4  2011/01/25  [Not refereed][Not invited]
  • 谷津リエ, 財津有里, 藤間憲幸, 白土博樹, 寺江聡, 石坂欣也, 工藤與亮, 佐々木真理  Jpn J Radiol  28-  (Supplement 1)  12  2010/07/25  [Not refereed][Not invited]
  • 吉田大介, 工藤與亮, 藤間憲幸, 財津有里, THA Khin Khin, 寺江聡, 白土博樹  日本医学放射線学会総会抄録集  69th-  S278-S279  2010/02/28  [Not refereed][Not invited]
  • Difference in CT Perfusion Maps among Commercially Available Software: Quantitative Analysis Using Identical Source Data of Acute Stroke Patients
    Kohsuke Kudo, Makoto Sasaki, Kei Yamada, Suketaka Momoshima, Taizo Kuroiwa, Hidetsuna Utsunomiya, Hiroki Shirato, Kuniaki Ogasawara  STROKE  40-  (4)  E114  -E114  2009/04  [Not refereed][Not invited]
  • 工藤 與亮, 谷津 リエ, 石坂 欣也, 財津 有里, 藤間 憲幸, 寺江 聡, 佐々木 真理  日本磁気共鳴医学会雑誌  29-  (1)  2009/02/15  [Not refereed][Not invited]
  • Makoto Sasaki, Eri Shibata, Kohsuke Kudo, Koujiro Tohyama  CLINICAL NEURORADIOLOGY-KLINISCHE NEURORADIOLOGIE  18-  (3)  147  -153  2008/08  [Not refereed][Not invited]
     
    The basics and the technique of magnetic resonance imaging (MRI) for visualizing the neuromelanin present in dopaminergic and noradrenergic nuclei in the substantia nigra pars compacta (SNc) and locus caeruleus (LC) are introduced. Neuromelanin, a black pigment produced during catecholamine synthesis, has paramagnetic T1-shortening effects. Conventional MRI techniques fail to depict the contrast generated by neuromelanin, but neuromelanin-sensitive T1-weighted fast spin echo technique at 3 T allows the direct visualization of the SNc and LC as hyperintense areas. In Parkinson's disease, neuromelanin-related signals from the SNc and LC are diminished, suggesting neuronal degeneration in both the nuclei. In depression and schizophrenia, signals from the LC are reduced while those from the SNc are augmented, suggesting monoamine and dopamine hypotheses, respectively. Neuromelanin-sensitive MRI is a promising technique to elucidate the pathologic or functional changes in the catecholamine neurons of the brain stem that occur in degenerative and psychiatric diseases.
  • 芹澤慈子, 工藤與亮, キン キンタ, 青山英史, 塚原亜希子, 寺江聡, 宮坂和男  Radiat Med  26-  8  2008/04/25  [Not refereed][Not invited]
  • 工藤與亮, 寺江聡, 白土博樹, 佐々木真理, 百島祐貴, 山田惠  日本医学放射線学会総会抄録集  67th-  S433  2008/02/28  [Not refereed][Not invited]
  • 藤間憲幸, 工藤與亮, 寺江聡, 財津有里, THA Khin Khin, 塚原亜希子, 浅野毅, 吉田大介, 飛騨一利, 白土博樹  日本医学放射線学会総会抄録集  67th-  S241  2008/02/28  [Not refereed][Not invited]
  • 石坂欣也, 工藤與亮, 藤間憲幸, 谷津リエ, 尾松美香, 寺江聡, 白土博樹  日本放射線技術学会総会学術大会予稿集  64th-  173  2008  [Not refereed][Not invited]
  • 藤間憲幸, 工藤與亮, 寺江聡, 財津有里, THA Khin Khin, 塚原亜希子, 吉田大介, 浅野剛, 谷津リエ, 石坂欣也, 白土博樹  日本神経放射線学会プログラム・抄録集  37th-  96  2008  [Not refereed][Not invited]
  • 財津有里, 藤間憲幸, 塚原亜希子, ター キンキン, 工藤與亮, 寺江聡, 白土博樹  日本神経放射線学会プログラム・抄録集  37th-  120  2008  [Not refereed][Not invited]
  • 石坂 欣也, 工藤 與亮  映像情報medical  39-  (10)  900  -904  2007/09  [Not refereed][Not invited]
  • THA Khin Khin, 寺江聡, 工藤與亮, 宮坂和男, 濱田晋輔, 佐々木秀直, 山本徹  Radiat Med  25-  20  2007/04/25  [Not refereed][Not invited]
  • 長野俊輔, 寺江聡, 工藤與亮, THA Khin Khin, 大川原舞, 吉田大介, 浅野剛, 宮坂和男, 飛騨一利, 岩崎喜信, 太田聡  Radiat Med  25-  1  2007/04/25  [Not refereed][Not invited]
  • 大川原舞, 工藤與亮, 寺江聡, THA Khin Khin, 吉田大介, 長野俊輔, 宮坂和男  Radiat Med  25-  1  2007/04/25  [Not refereed][Not invited]
  • 芹澤慈子, THA Khin K, 青山英史, 工藤與亮, 加藤徳雄, 寺江聡, 白土博樹  日本医学放射線学会学術集会抄録集  66th-  S225  2007/02/28  [Not refereed][Not invited]
  • Susceptibility Weighted Imagingを用いた脊髄静脈描出における至適条件の検討
    石坂 欣也, 岡 美香, 宗像 大和, 工藤 與亮, 吉田 有里  日本放射線技術学会雑誌  62-  (9)  1297  -1298  2006/09  [Not refereed][Not invited]
  • 吉田有里, 工藤与亮, 寺江聡, 宮坂和男  日本医学放射線学会学術集会抄録集  65th-  S95  2006/02/25  [Not refereed][Not invited]
  • 工藤与亮, 佐々木真理, 寺江聡, 吉田有里, 宮坂和男  日本医学放射線学会学術集会抄録集  65th-  S145  2006/02/25  [Not refereed][Not invited]
  • Shunsuke Onodera, Satoshi Terae, Kohsuke Kudo, Khin Khin Tha, Kazuo Miyasaka, Kazutoshi Hida, Yoshinobu Iwasaki, Satoshi Ota  European Journal of Radiology Extra  57-  (2)  41  -45  2006/02  [Not refereed][Not invited]
     
    Primary intramedullary spinal cord germinoma is a rare neoplasm and sensitive to radiotherapy and chemotherapy. In this report, a 16-year-old girl presented with pain and numbness of both thighs, difficulty in walking, followed by urinary disturbance. Neurological examination revealed motor weakness, hypotonicity, reduced deep tendon reflexes of both lower limbs, and decrease in sensation below Th12 level. MR examination demonstrated intramedullary mass lesion of the lower thoracic spinal cord. On T2-weighted images, the lesion was heterogeneous but mostly slightly hyperintense. There were small cysts within the tumor. On T1-weighted images, the lesion was mostly hypointense. Mild and heterogeneous enhancement was observed on postcontrast T1-weighted images. No other neoplastic lesion has been found inside and outside the central nervous system. The patient underwent surgery, and the intramedullary lesion was almost totally resected. The lesion was diagnosed as germinoma histologically. Analysis of cerebrospinal fluid (CSF) obtained during operation revealed elevated level of beta-subunit of human chorionic gonadotrophin (beta-hCG). Literature review revealed that MRI findings of intramedullary spinal cord germinomas are frequently nonspecific, but these tumors sometimes have small intratumoral cysts. Germinomas should be included in the differential diagnosis, especially when an intramedullary spinal cord tumor is found in the thoracic or thoraco-lumbar region in a young adult patient. Elevated level of beta-hCG in CSF strongly suggests germinoma. © 2005 Elsevier Ireland Ltd. All rights reserved.
  • THA Khin Khin, 寺江聡, 工藤與亮, 相馬広幸, 吉田有里, 佐々木秀直, 宮坂和男  日本神経放射線学会プログラム・抄録集  35th-  119  2006  [Not refereed][Not invited]
  • 工藤與亮, 佐々木真理, 寺江聡, 吉田有里, タ キンキン, 宮坂和男  日本神経放射線学会プログラム・抄録集  35th-  89  2006  [Not refereed][Not invited]
  • 工藤与亮, 寺江聡, 佐々木真理, 黒岩大三, 宇都宮英綱, 宮坂和男  日本医学放射線学会学術集会抄録集  64th-  S360  2005/02/25  [Not refereed][Not invited]
  • 工藤與亮, 笹木工, 寺江聡, 宮坂和男  日本神経放射線学会プログラム・抄録集  34th-  119  2005  [Not refereed][Not invited]
  • 高橋有美, 鈴木大介, 山沢弘州, 八鍬聡, 北谷智彦, 須藤章, 斉藤伸治, 工藤与亮, 寺江聡  脳と発達  36-  (4)  351  2004/07/01  [Not refereed][Not invited]
  • 工藤与亮, 寺江聡, キンキン ター, 宮坂和男  日本医学放射線学会雑誌  64-  (4)  256  2004/05/25  [Not refereed][Not invited]
  • 浅野剛, 寺江聡, 工藤与亮, 牛越聡, 宮坂和男, 黒田敏, 石川達哉  脳卒中  26-  (1)  198  2004/03/01  [Not refereed][Not invited]
  • 工藤与亮, 寺江聡, 宮坂和男  日本医学放射線学会雑誌  64-  (2)  S325  2004/02/25  [Not refereed][Not invited]
  • 笹木工, 山下道明, 孫田恵一, 寺江聡, 工藤与亮  日本放射線技術学会総会学術大会予稿集  60th-  110  2004/02/20  [Not refereed][Not invited]
  • CT Perfusionの標準化
    映像情報  36(6)-  2004  [Not refereed][Not invited]
  • 浅野剛, 牛越聡, 工藤与亮, 寺江聡, 宮坂和男, 黒田敏, 石川達哉, 岩崎喜信  日本脳神経外科学会総会抄録集  62nd-  (CD-ROM Abstracts)  105  2003/10/01  [Not refereed][Not invited]
  • 笹木工, 山下道明, 孫田恵一, 寺江聡, 工藤与亮, 加藤千恵次  日本放射線技術学会雑誌  59-  (9)  1032  2003/09/20  [Not refereed][Not invited]
  • Sequential determination of orbital fat volume and extraocular muscle thickness following radioiodine therapy in Graves' disease: Evaluation by multi-detector CT.
    K Nakada, K Hirata, K Kudoh, S Terae, T Takei, T Kaji, E Tsukamoto, N Tamaki  JOURNAL OF NUCLEAR MEDICINE  44-  (5)  335P  -336P  2003/05  [Not refereed][Not invited]
  • 脊髄・脊椎のヘルニア
    臨床放射線  48(6):695-710-  2003  [Not refereed][Not invited]
  • 工藤与亮, 石井亜紀, 尾松徳彦, 寺江聡, 浅野剛, 宮坂和男  日本神経放射線学会プログラム・抄録集  32nd-  117  2003  [Not refereed][Not invited]
  • Quantitative CT perfusion imaging in patients with severe carotid stenosis or occlusion: Comparison with CO2PET-CBF study using large vessel elimination method
    K Kudo, S Terae, C Kato, S Kuroda, N Tamaki, K Miyasaka  RADIOLOGY  225-  204  -204  2002/11  [Not refereed][Not invited]
  • MR imaging features of myxopapillary ependymoma correlation with pathological findings: Dot and streak sign
    Y Watanabe, S Terae, K Kudo, K Miyasaka  RADIOLOGY  225-  206  -207  2002/11  [Not refereed][Not invited]
  • 海東恵美子, 寺江聡, 工藤与亮, キンキンタ, 宮坂和男, 小林良二, 依田弥菜子, 阿部なお美, 皆川公男  日本医学放射線学会雑誌  62-  (12)  708  2002/10/25  [Not refereed][Not invited]
  • WATANABE Yoshiaki  日本小児放射線学会雑誌 = Journal of Japanese Society of Pediatric Radiology  18-  (0)  2002/04/25  [Not refereed][Not invited]
  • Quantitative CBF and CBV measurements by dynamic perfusion CT: A direct comparison with PET using semi-automated co-registration program
    K Kudo, S Terae, C Kato, M Oka, N Tamaki, K Miyasaka  RADIOLOGY  221-  140  -140  2001/11  [Not refereed][Not invited]
  • Multi-objective frequency processing (MFP) and pattern enhancement processing for mammography (PEM)
    K Kudo, R Kishimoto, T Nambu, O Kamada, R Yamazaki, K Miyasaka  RADIOLOGY  217-  163  -163  2000/11  [Not refereed][Not invited]
  • 三次元画像の基礎と応用
    整形・災害外科  40(10):1227-1233-  1997  [Not refereed][Not invited]

Industrial Property Rights

  • 医用画像処理装置及び医用画像の処理法 「CT Perfusionにおける血管除去法と画像」
    2004-108291
  • Vascular Pixel Elimination in CT Perfusion
    2004-108291

Awards & Honors

  • 2019/09 日本磁気共鳴医学会 Excellent Paper Award
     Indirect Proton MR Imaging and Kinetic Analysis of 17O-Labeled Water Tracer in the Brain 
    受賞者: KUDO Kohsuke
  • 2018/04 Japanese Society of Radiology JJR Excellent Reviewer Award in 2017
     
    受賞者: KUDO Kohsuke
  • 2012/09 Japanese Society of Magnetic Resonance Imaging Academic Encouragement Award
     定量的磁化率マップ(QSM)を利用したOEF画像:主幹動脈病変患者におけるPETとの比較 
    受賞者: KUDO Kohsuke
  • 2010/02 Japanese Society of Neuroradiology Silver Award
     デジタルファントムを用いたCT 灌流画像解析ソフトの精度検証 
    受賞者: KUDO Kohsuke
  • 2010/02 北海道大学医学部同窓会 Furate Research Encouragement Award
     CT灌流画像を用いた脳血流解析に関する研究 
    受賞者: 工藤 與亮
  • 2008/09 Japanese Society of Magnetic Resonance Imaging Academic Encouragement Award
     SWIを用いた定量的脳血流マップの開発 
    受賞者: KUDO Kohsuke
  • 2008/04 Japanese Society of Radiology Cyper Rad Award
     Perfusion Mismatch Analyzer (PMA):自動化・標準化された灌流画像解析ソフトウェア 
    受賞者: KUDO Kohsuke
  • 2006/04 Japanese Society of Radiology Bronze Award
     Standardization of CT and MR Perfusion Analysis 
    受賞者: KUDO Kohsuke
  • 2006/03 World Neuroradiology Symposium Travel Award
     Standardization of Analysis Methods in CT and MR Perfusion Imaging 
    受賞者: KUDO Kohsuke
  • 2005/10 北海道脳PET・SPECT研究会 Excellent Paper Award
     CT Perfusionの定量性に関する検討-PETとの比較- 
    受賞者: KUDO Kohsuke
  • 2005/02 Japanese Society of Neuroradiology Excellent Paper Award
     脳血流ファントムを用いた低線量CT Perfusionの限界の検討 
    受賞者: KUDO Kohsuke
  • 2004/02 Radiological Society of North America Certificate of Merit
     Optimization of Scan Protocol and Analyzing Method for Low Dose CT Perfusion: How to Reduce Radiation Dose in CT Perfusion Study 
    受賞者: KUDO Kohsuke
  • 2004/02 Japanese Society of Neuroradiology Kato Award
     Quantitative cerebral blood flow measurement with dynamic perfusion CT using the vascular-pixel elimination method: comparison with H2(15)O positron emission tomography 
    受賞者: KUDO Kohsuke
  • 2003/06 北海道大学放射線医学講座同門会 Wakabayashi Award
     Quantitative cerebral blood flow measurement with dynamic perfusion CT using the vascular-pixel elimination method: comparison with H2(15)O positron emission tomography 
    受賞者: KUDO Kohsuke
  • 2003/02 Japanese Society of Neuroradiology Excellent Paper Award
     頭蓋内静脈洞におけるMRVと血流測定:息止めによる血流速度および方向の生理的変動について 
    受賞者: KUDO Kohsuke
  • 2001/02 Japanese Society of Neuroradiology Excellent Paper Award
     Multi-Detector Row CTを用いたAdamkiewicz動脈および前脊髄動脈の描出 
    受賞者: KUDO Kohsuke
  • 1998/12 Radiological Society of North America Certificate of Merit
     Effect of Compression Parameters in Wavelet Method: Analysis of Image Quality and Compression Errors in CT and MR Images 
    受賞者: KUDO Kohsuke
  • 1997/12 Radiological Society of North America Certificate of Merit
     ROC Analysis of Digital Image Data Compression: Clinically Acceptable Compression Ratio of CT and MR Images of the Brain 
    受賞者: KUDO Kohsuke

Research Grants & Projects

  • Visualization of Cellular Metabolism using O-17 Oxygen MRI
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2017/04 -2020/03 
    Author : 工藤 與亮, 小牧 裕司, 阿保 大介, 加藤 扶美
     
    O-17酸素ガスおよびO-17標識グルコースが高価であるため、実験動物を用いたin vivoの系の前に、まずは培養細胞を用いたin vitroの系で検討を進めた。具体的には、代表的な浮遊細胞であるJurkat細胞(ヒト急性T細胞性白血病細胞由来細胞株)をRPMI1640培地とともにプラスチックシリンジに密閉し、CO2インキュベーター内(37℃, 5% CO2)で至適の期間培養する系を確立した。この際、O-17酸素ガスあるいはO-17標識グルコース存在下、非存在下で適切にコントロール群を設定し、回収した培養液をFSE系のシークエンスで撮像し、O-17標識“代謝水”による信号変化が得られるかを確認する実験系としたが、培養期間の検討やpH変動などの課題があり、実際のMRI撮像は次年度となった。 O-17水の脳脊髄液腔内投与実験を正常のラットで行った。正常のラットの大槽穿刺を行い、マイクロカニューレを留置した状態でMRI撮像を開始し、経時的にMRI撮像を行う実験系を確立した。留置したカニューレからGd造影剤を投与することで脳脊髄液から脳実質への造影剤以降を視覚的に確認することができた。しかし、カニューレ留置の手技が安定せず、カニューレの位置が浅く造影剤投与ができなかったり、カニューレの位置が深く脳実質に刺さってしまったりしたため、O-17水の投与は数例になった。投与したO-17水は脳室内への移行が確認されたが、気泡の混入や出血などがあったため長時間のMRI撮像追跡は困難であった。一方、ヒトでの検討として、正常圧水頭症や認知症の患者を対象とした特定臨床研究としてIRBを申請した。 O-17水の静脈内投与実験として、ASLモデルマウスでの血管透過性異常などの解析を計画した。モデルマウスの調達先を確保し、MRI撮像のプロトコルを作成した。
  • 拡散・灌流・磁化率MRIの統合による多角的無侵襲脳循環代謝イメージング法の確立
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2017/04 -2020/03 
    Author : 佐々木 真理, 小笠原 邦昭, 工藤 與亮, 平野 照之
     
    脳循環代謝検査は脳卒中の予防や診療において重要な役割を果たしているが、ゴールドスタンダードであるPETやSPECTは、侵襲性・汎用性・即時性・経済性の点で課題が多い。そこで、MRIによる拡散・灌流・磁化率画像を統合することで、脳血流量(CBF)、血管反応性(CVR)、脳血液量(CBV)、脳酸素摂取率(OEF)などの機能画像を高精度に算出する独自の画像解析法を開発し、急性期脳梗塞や慢性脳虚血における精度検証を行うことで、PET・SPECTの代替となりうる次世代無侵襲脳循環代謝検査法を確立する。本研究によって、発症・合併症予測や重症度評価が容易となり、治療戦略の決定や有害事象の予防に寄与することが期待できる。当該年度は以下の研究を実施した。 【MRIによる多角的無侵襲撃脳循環代謝解析法の開発】IVIMでは、昨年度改良した独自の解析ソフトエアと最適化した解析パラメータを用い、IVIM-CBVの精度をアセタゾラミドSPECT-CVRと比較検証した。ASLでは、昨年度開発したHadamard符号化に加え低解像度multiPLDによるATT補正法を新たに実装し、CBFの精度をSPECTと比較検証した。 【MRI撮像法の標準化と解析アルゴリズムの最適化】昨年度開発したQSM-OEF解析ソフトウエアにおいて、磁場強度や機種毎にフィルタリング・血管除去パラメータを最適化した。 【PET・SPECTとの比較によるMRI脳循環代謝検査法の精度検証】CEA術前の慢性脳虚血患者20名およびもやもや病20名に対し、3T MRIを用いてIVIM・ASL・QSM元画像を撮像し、PETまたはSPECTも撮像した。術中・術後イベントや予後についての情報収集を随時行った。また、急性期脳梗塞患者20名に対し、3T MRIを用いてQSM元画像などを撮像し、有害事象や予後についての情報収集を随時行った。
  • マイクロカテーテルのカニュレーション難易度解明と科学的トレーニングシステムの開発
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2017/04 -2020/03 
    Author : 曽山 武士, 工藤 與亮, 阿保 大介, 作原 祐介
     
    平成29年度は、予備検討として、従来の先端非可動型マイクロカテーテルを使用してカニュレーションできなかった、またはカニュレーションできたが60分以上 を要した標的血管を "Challenging Vessel" と定義し、14のChallenging Vesselに先端非可動型マイクロカテーテルと先端可動型マイクロカテーテルを用いてカ ニュレーションを試みた際の、カニュレーションの成功率とカニュレーションに要する時間を後方視的に解析し、結果を2017年9月のIVR research meeting(東 京)で発表した。この結果については現在論文を執筆中である。 また、実験で使用する血管模型を作成するために、当初は院内に設置されている3Dプリンターを使用する予定であったが、院内の3Dプリンターでは硬い素材で 血管模型を作らざるをえず、より本物の血管に近づけるため、平成29年度の日本IVR学会総会と日本医学放射線学会秋季大会の3Dプリンターのセッションに参加 して、近年開発された柔らかい素材で血管模型を作成する方法を学び、これを作成できるCanon社の3Dプリンター「Form 2」を購入した。 平成30年度は、前年度に購入した3Dプリンター (Foam2/キャノンライフケアソリューションズ)を使用して、柔軟性のある素材で、内腔のある血管模型(中空モデル)の作成方法を確立した。我々が確立したのは、①Dynamic CT(早期動脈相)のDICOM画像をInVesaliusでSTLに変換する、②MeshLabでトリミング&修正する、③Meshmixerで中空構造を作成する、という手順である。この方法により、最大で長径11cmの腹部血管模型を、壁の厚さ0.5mmで作成するに至った。
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2016/04 -2019/03 
    Author : Uwano Ikuko, KUDO Kohsuke, YAMASHITA Fumio
     
    We investigated whether oxygen extraction fraction (OEF) maps generated by magnetic resonance quantitative susceptibility mapping (QSM) at high-field MRI enabled detection of OEF changes when compared with those obtained with PET. OEF ratios on QSM-OEF images at 7 Tesla and 3 Tesla MRI showed a good correlation with those on PET-OEF images in patients with unilateral steno-occlusive internal carotid artery/middle cerebral artery lesions, suggesting that noninvasive OEF measurement by MRI can be a substitute for PET. In addition, we found that preoperative QSM-OEF at 7 Tesla could identify patients at risk for cerebral hyperperfusion following carotid endarterectomy, and that the 7 Tesla QSM-OEF at 5 min after acetazolamide administration mostly correlates with hemodynamics in the patients with major cerebral arterial steno-occlusive disease. Moreover, correlations between QSM-OEF and PET-OEF in patients with chronic ischemia were improved when using high-resolution source images.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2014/04 -2017/03 
    Author : Kudo Kohsuke
     
    Signal simulations for the various tissue were conducted using theoretical equations of MRI signals. Good correlations were noted between signal simulation and O-17 phantom signal, and conversion method from MRI signal to O-17 concentration was determined. Based on the MRI scans of normal volunteers, scan method with FSE sequence was established, and development of algorithm for quantitative analysis of cerebral blood flow. Manufacturing of O-17 oxygen was established, and inhalation apparatus of O-17 was designed. Smaller O-17 phantom was created, and MRI scans with animal MRI were performed. Good image contrast was obtained for marmosets with the administration of O-17 water.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2014/04 -2017/03 
    Author : Sakuhara Yusuke
     
    1. The digital phantom method can be used to create various virtual lesions on the displayed ultrasonographic (US) image by altering original data. In addition, The gray scale of the displayed virtual US image might be appropriately adjusted in order to the real US imaging in the clinical situations. 2. Various diseases, such as tumorous lesions, stones, varices, ascites, etc.) can be presented on the virtual US images created by the digital phantom method. 3. Original CT or MR image data can be altered to other images on the display resembling those of US images by the digital phantom method . 4. The digital phantom method might be applied to the training system of the US-guided percutaneous interventional procedures.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2014/04 -2017/03 
    Author : Tha KhinKhin
     
    Electrical conductivity is a property of a material to conduct electric current. Different materials are known to have different electrical conductivity values, ranging from almost zero (insulators) to several million siemens per meter (S/m) (conductors). Living tissues are also reported to have variable electrical conductivity values -- fat and bone have lower values, whereas the cerebrospinal fluid (CSF) and blood have higher values. Tumors, especially malignant ones, are reported to have higher values than the normal tissues. This study aimed at the establishment of noninvasive electrical conductivity measurement technique by using MRI and to evaluate the accuracy of this technique. It was observed that the noninvasive electrical conductivity measurement by MRI was highly repeatable and valid. In addition, the results suggested that information about electrical conductivity can be useful in distinguishing glioblastoma from lower grade gliomas.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
    Date (from‐to) : 2013/04 -2015/03 
    Author : GOODWIN Jonathan, PARKES Laura, KUDO Kohsuke, SASAKI Makoto
     
    OEF post processing techniques were demonstrated in a healthy population during concious sedation (Goodwin et al 2014). Subsequent work focused on development of CBF measurement using ASL MRI; necessary for developing a combined imaging approach to CMRO2 measurement. However, there were several technical limitations. Initial efforts focused on ASL using 7T MRI, but it became apparent that this approach was no longer available option with our current 7T system. Instead, collaborative work commenced on development of 3T ASL with multi-banding and Look Locker readout. This involved 6 months in the University of Manchester, UK. If successful, this technique would increase brain coverage allow CBF arrival time measurement. A number of experiments were carried out to try and establish this method, in collaboration with Philips engineers, and a number of technical challenges were discovered, which ultimately were not resolved prior to the end of the Kakenhi period. This research is ongoing.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
    Date (from‐to) : 2013/04 -2015/03 
    Author : UWANO Ikuko, KUDO Kohsuke, OGASAWARA Kuniaki, BEPPU Takaaki, SASAKI Makoto
     
    In this study, we evaluated the performance and efficacy for intensity inhomogeneity correction of various sequences of the human brain in 7 Tesla MRI using the extended version of the unified segmentation algorithm, and we found all of these intensity inhomogeneities were successfully corrected and the contrast between different tissue types was maintained after inhomogeneity correction. In addition, we investigated whether oxygen extraction fraction (OEF) maps that were generated with a quantitative susceptibility mapping (QSM) technique at 7 Tesla would demonstrate OEF changes in patients with major cerebrovascular steno-occlusive disease compared with OEF maps that were generated with PET, and as a result the OEF ratios on QSM-OEF maps at 7 Tesla correlated well with those on PET-OEF maps in patients with steno-occlusive cerebrovascular diseases.
  • MRI位相差情報を用いた無侵襲脳血流定量計測法の開発と臨床応用
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2009 -2011 
    Author : 工藤 與亮, 佐々木 真理, 小笠原 邦昭, 寺江 聡
     
    本研究の目的は超高磁場MRI装置による位相画像を用いて、非侵襲的で定量的な脳脊髄血流解析法を開発・臨床応用することである。 既存の複数の3T-MRI装置(GE社、Philips社)を用いた磁化率強調画像の位相画像から酸素飽和度を算出するプログラムを作成し、酸素飽和度の定量値算出及び脳血流変化のマップ化を行った。さらに、酸素飽和度から酸素摂取率(OEF)を算出するプログラムを作成し、呼吸負荷や薬物負荷によりOEFが有意に変化することが確認された。これらの研究成果は国際学会での発表を行い、論文投稿中である。また、内頚動脈狭窄患者でも脳の位相画像を撮像し、安静時でもOEFの上昇が観察されたが、さらにOEFマップ作成のアルゴリズム改良を行っている。今までは2回のMRI撮像を行って位相変化から酸素飽和度やOEFの変化率を算出できていたが、それを1回のMRI撮像で絶対値として値を算出できるようにプログラム・アルゴリズムを改変中である。患者群ではDiamox負荷での経時的変化の撮像も行っており、PETでのOEFマップとの比較や、MRIのASL法による脳血流マップとの比較を行っている。 また、同時に脳血流解析の基礎的検討として数値ファントムを開発し、解析プログラムの精度検証を行っているが、市販ソフトウェアでの解析結果がまとまったので論文作成中である。さらに、各市販ソフトウェアメーカへの結果のフィードバックも行っている。
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2008 -2010 
    Author : TERAE Satoshi, INOUE Takeshi, NAKAGAWA Shin, KUDO Kohsuke
     
    Diffusion tensor imaging (DTI) was conducted in 13 treatment-resistant, 12 nontreatment-resistant, and 19 drug-naive patients with major depression. As compared with normal control subjects, a voxel-based analysis revealed significant decrease in fractional anisotropy (FA) in the right frontal white matter in the treatment-resistant patients. Histogram analysis demonstrated significant decrease in peak position of FA histogram of the drug-naive patients. No significant correlation was observed between the FA abnormality and clinical severity as assessed by HDRS, GAF, and MADRS.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas
    Date (from‐to) : 2005 -2009 
    Author : SHIRATO Hiroki, KANEKO Junichi, NISHIYAMA Syusuke, KATOH Chietsugu, AOYAMA Hidefumi, SEKI Koh-ichi, ONIMARU Rikiya, NISHIOKA Takeshi, MORITA Koichi, DATE Hiroyuki, TAKADA Eiji, TOMIOKA Satoshi, KUDO Kohsude, ONODERA Yuya, KAMISHIMA Tamotsu, ONIMARU Rikiya, SHIMIZU Shinichi, SAKUHARA Yusuke, OYAMA Noriko, ABO Daisuke, TAGUCHI Hiroshi
     
    We developed a four-dimensional (4-D, space and time) focal positron emission localizer, FPEL, using two sets of BGO scintillators, photo-electric multiplier, and collimators. A narrow (5-mm in diameter) 45-MeV electron beam was controlled to irradiate a target with an accuracy of 0.1mm in 4D coordinates automatically if the amount of positron emitters at the target exceeds the threshold. A mouse model was established to irradiate the tumor in which FDG is accumulated. Using the FPEL, 45-MeV electron beam hit the tumor in mice which move in front of the beam exit with the amplitude resembling human respiration. Tumor without fiducial gold marker disappeared within a week after the irradiation. Basis for 4D stereotacic radiotherapy was established successfully.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
    Date (from‐to) : 2006 -2008 
    Author : SHIRATO Hiroki, HONMA Sato, TAMAKI Nagara, KUGE Yuji, DATE Hiroyuki, KIYANAGI Yoshiaki, HATAKEYAMA Masanori, KANEKO Junichi, MIZUTA Masahiro, INUBUSHI Masayuki, TADANO Shigeru, TAMURA Mamoru, HAYAKAWA Kazushige, MATSUNAGA Naofumi, ISHIKAWA Masayori, AOYAMA Hidefumi, SAKUHARA Yusuke, ONIMARU Rikiya, ABO Daisuke, OITA Masataka, KAMISHIMA Tamotsu, TERAE Satoshi, KUDO Kohsuke, ONODERA Yuya, OMATSU Tokuhiko, SHIMIZU Shinichi, NISHIMURA Takashi, SUZUKI Ryusuke, GERARD Bengua
     
    いままでの先端放射線医療に欠けていた医療機器と患者のinteractionを取り入れた放射線治療を可能にする。臓器の動き・腫瘍の照射による縮小・免疫反応などは、線量と時間に関して非線形であり、システムとしての癌・臓器の反応という概念を加えることが必要であることが示唆された。生体の相互作用を追求していく過程で、動体追跡技術は先端医療のみならず、基礎生命科学でも重要な役割を果たすことがわかった。
  • Development of oxygen molecular imaging of the brain
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2006 -2007 
    Author : TERAE Satoshi, YAMAMOTO Toru, KATOH Chietsugu, KURODA Satoshi, KUDO Kohsuke
     
    Using susceptibility-weighted imaging (SWI) of MRI (magnetic resonance imaging), we tried to develop a method to measure regional oxygen consumption of the brain. We evaluated local inhomogeneity of the magnetic field caused by deoxyhemoglobin (deoxyHb) in the cerebral vein using the phase information of SWI. We found that the local inhomogeneity observed by SWI is strongly affected by an angle between the longitudinal axis of the vein and the direction of the static magnetic field of the MRI unit. Therefore, the angle has to be incorporated to calculate local deoxyHb concentration of the vein. In normal volunteers, the phase shift increased under hyperventilation and it decreased under breath hold. Changes in oxygen saturation of the veins and in cerebral blood flow, that were calculated by using the difference in phase shift, showed the same results. This indicates that we can measure deoxyHb concentration of the cerebral veins by SWI if we can establish a reference of relationship between the amount of phase shift and deoxyHb concentration in the vein. In a patient with acute cerebral infarct, the largest local phase shift was observed in the infracted area. The phase shift was the largest immediately after the onset, and it decreased gradually during the first 20 days. In contrast, in another patient with chronically impaired blood flow and increased oxygen extraction fraction (OEF) in left anterior and middle cerebral artery territory that was caused by left internal carotid artery occlusion, there was no difference in the phase shift between the ischemic area and the contralateral healthy area. These results imply that SWI can detect increased deoxyHb in the veins of acute ischemic area, but cannot detect increased OEF in chronic phase.
  • CT/MR Perfusionにおける定量解析
  • Quantitative CT/MR perfusion analysis of cerebral blood flow

Educational Activities

Teaching Experience

  • 医学総論
    開講年度 : 2018
    課程区分 : 博士後期課程
    開講学部 : 医学研究科
  • Master's Thesis Research in Medical Sciences
    開講年度 : 2018
    課程区分 : 修士課程
    開講学部 : 医学院
    キーワード : 放射線医療 放射線診断 放射線治療 癌 CT MRI  radiation medicine, diagnostic radiology, radiation oncology, cancer, CT, MRI
  • 全科臨床実習
    開講年度 : 2018
    課程区分 : 学士課程
    開講学部 : 医学部
  • Inter-Graduate School Classes(General Subject):Natural and Applied Sciences
    開講年度 : 2018
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
  • Basic Principles of Medicine
    開講年度 : 2018
    課程区分 : 修士課程
    開講学部 : 医学院
    キーワード : 放射線診断、放射線治療 Diagnostic Radiology, Radiation Oncology
  • Diagnostic Radiology for Biomedical Science and Engineering
    開講年度 : 2018
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 画像診断 CT MRI
  • Radiologic Anatomy for Biomedical Science and Engineering
    開講年度 : 2018
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 画像解剖 CT MRI
  • Dissertation Research in Medical Sciences
    開講年度 : 2018
    課程区分 : 博士後期課程
    開講学部 : 医学院
    キーワード : 放射線医療 放射線診断 放射線治療 癌 CT MRI  radiation medicine, diagnostic radiology, radiation oncology, cancer, CT, MRI
  • Dissertation Research in Clinical Medicine
    開講年度 : 2018
    課程区分 : 博士後期課程
    開講学部 : 医学院
    キーワード : 放射線医療 放射線診断 放射線治療 癌 CT MRI  radiation medicine, diagnostic radiology, radiation oncology, cancer, CT, MRI
  • Principles of Medicine
    開講年度 : 2018
    課程区分 : 博士後期課程
    開講学部 : 医学院
    キーワード : 放射線医学、放射線診断学、画像診断、インターベンショナル、放射線治療、癌、がんプロフェッショナル Radiation medicine, diagnostic radiology, imaging diagnosis, interventional radiology, radiotherapy, cancer, cancer professional
  • Principles of Medicine
    開講年度 : 2018
    課程区分 : 博士後期課程
    開講学部 : 医学院
  • Diagonstic Radiology (Normal Anatomy)
    開講年度 : 2018
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 正常解剖 Normal anatomy 画像診断 Diagnostic imaging  放射線医学 radiology


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